# Opinion polling for the 2015 Portuguese legislative election

In the run up to the 2015 Portuguese legislative election, various organisations carried out opinion polling to gauge voting intention in Portugal. Results of such polls are displayed in this article.
The date range for these opinion polls are from the previous general election, held on 5 June 2011, to the day the next election was held, on 4 October 2015.

## Party vote

Poll results are listed in the table below in reverse chronological order, showing the most recent first. The highest percentage figure in each polling survey is displayed in bold, and the background shaded in the leading party's colour. In the instance that there is a tie, then no figure is shaded but both are displayed in bold. The lead column on the right shows the percentage-point difference between the two parties with the highest figures. Poll results use the date the survey's fieldwork was done, as opposed to the date of publication.
| Date | Polling Firm | Sample size | | | | | | | | | Others | Lead |
| 4 Oct 2015 | 2015 legislative election | 55.9% | 38.6 | 38.6 | 32.3 | 8.3 | 10.2 | 0.4 | 0.7 | 1.1 | 8.4 | 6.3 |
| 4 Oct | Aximage | | 40.2 | 40.2 | 32.3 | 8.9 | 9.4 | | | | 9.2 | 7.9 |
| 4 Oct | Eurosondagem | 46,626 | 38.3 | 38.3 | 31.3 | 7.9 | 9.3 | | | | 13.2 | 7.0 |
| 4 Oct | Intercampus | 17,726 | 39.2 | 39.2 | 31.7 | 8.5 | 10.2 | | | | 10.4 | 7.5 |
| 4 Oct | UCP–CESOP | 25,898 | 40.5 | 40.5 | 32.5 | 8.0 | 9.5 | | 1.0 | | 8.5 | 8.0 |
| Exit polls |||||||||||||
| 26 Sep–1 Oct | Aximage | 1,387 | 39.1 | 39.1 | 32.5 | 9.2 | 9.0 | | | | 10.2 | 6.6 |
| 26–30 Sep | UCP–CESOP | 1,070 | 39.0 | 39.0 | 34.0 | 10.0 | 8.0 | | | | 9.0 | 5.0 |
| 22–30 Sep | Intercampus | 1,013 | 37.2 | 37.2 | 32.9 | 8.8 | 7.9 | 0.5 | 0.5 | 1.7 | 10.5 | 4.3 |
| 29 Sep | Aximage | 200 | 40.3 | 40.3 | 31.8 | 8.1 | 7.1 | | | | 12.7 | 8.5 |
| 26–29 Sep | Intercampus | 1,008 | 38.4 | 38.4 | 32.1 | 8.4 | 7.9 | | | | 13.2 | 6.3 |
| 25–29 Sep | UCP–CESOP | 1,010 | 39.0 | 39.0 | 33.0 | 11.0 | 8.0 | | | | 9.0 | 6.0 |
| 24–29 Sep | Eurosondagem | 2,067 | 37.7 | 37.7 | 32.7 | 9.4 | 6.7 | | | | 13.5 | 5.0 |
| 22–29 Sep | Marktest | 1,607 | 41.0 | 41.0 | 28.6 | 9.3 | 8.7 | | 0.8 | 0.7 | 10.9 | 12.4 |
| 28 Sep | Aximage | 200 | 39.0 | 39.0 | 32.1 | 8.2 | 7.1 | | | | 13.6 | 6.9 |
| 25–28 Sep | Intercampus | 1,008 | 38.8 | 38.8 | 31.6 | 8.2 | 7.9 | | | | 13.5 | 7.2 |
| 24–28 Sep | UCP–CESOP | 1,071 | 40.0 | 40.0 | 34.0 | 10.0 | 7.0 | | | | 9.0 | 6.0 |
| 27 Sep | Aximage | 199 | 38.4 | 38.4 | 31.8 | 8.4 | 7.1 | | | | 14.3 | 6.6 |
| 26–27 Sep | UCP–CESOP | 3,302 | 38.0 | 38.0 | 32.0 | 9.0 | 9.0 | | 1.0 | 1.0 | 10.0 | 6.0 |
| 24–27 Sep | Intercampus | 1,025 | 37.9 | 37.9 | 32.1 | 9.1 | 7.5 | | | | 13.4 | 5.8 |
| 23–27 Sep | UCP–CESOP | 1,075 | 41.0 | 41.0 | 34.0 | 9.0 | 7.0 | | | | 9.0 | 7.0 |
| 26 Sep | Aximage | 200 | 37.9 | 37.9 | 32.3 | 8.6 | 7.0 | | | | 14.2 | 5.6 |
| 23–26 Sep | Intercampus | 1,025 | 38.1 | 38.1 | 33.0 | 9.0 | 6.7 | | | | 13.2 | 5.1 |
| 22–26 Sep | UCP–CESOP | 936 | 43.0 | 43.0 | 33.0 | 8.0 | 7.0 | | | | 9.0 | 10.0 |
| 25 Sep | Aximage | | 37.7 | 37.7 | 32.3 | | | | | | 30.0 | 5.4 |
| 22–25 Sep | Intercampus | 1,025 | 37.5 | 37.5 | 32.8 | 8.9 | 6.7 | | 0.3 | 1.1 | 12.7 | 4.7 |
| 21–25 Sep | UCP–CESOP | 1,027 | 42.0 | 42.0 | 35.0 | 8.0 | 7.0 | | | | 8.0 | 7.0 |
| 24 Sep | Aximage | | 37.7 | 37.7 | 32.6 | | | | | | 29.7 | 5.1 |
| 21–24 Sep | Intercampus | 1,024 | 37.0 | 37.0 | 32.3 | 9.2 | 6.1 | | | 1.1 | 14.3 | 4.7 |
| 20–24 Sep | UCP–CESOP | 1,046 | 41.0 | 41.0 | 34.0 | 9.0 | 7.0 | | | | 9.0 | 7.0 |
| 18–24 Sep | Aximage | 710 | 37.9 | 37.9 | 32.0 | 9.0 | 7.1 | | | | 14.0 | 5.9 |
| 23 Sep | Aximage | 100 | 37.0 | 37.0 | 33.4 | 7.6 | 6.5 | | | | 15.5 | 3.6 |
| 20–23 Sep | Intercampus | 1,017 | 37.9 | 37.9 | 32.9 | 7.8 | 6.0 | | | | 15.4 | 5.0 |
| 19–23 Sep | UCP–CESOP | 891 | 40.0 | 40.0 | 35.0 | 9.0 | 8.0 | | | | 8.0 | 5.0 |
| 17–23 Sep | Eurosondagem | 1,548 | 35.5 | 35.5 | 36.0 | 10.1 | 5.0 | | 1.5 | 1.9 | 10.0 | 0.5 |
| 22 Sep | Aximage | 103 | 36.3 | 36.3 | 34.3 | 7.9 | 6.2 | | | | 15.3 | 2.0 |
| 19–22 Sep | Intercampus | 1,007 | 38.9 | 38.9 | 34.1 | 8.3 | 4.8 | | | | 13.9 | 4.8 |
| 18–22 Sep | UCP–CESOP | 828 | 40.0 | 40.0 | 34.0 | 10.0 | 8.0 | | | | 8.0 | 6.0 |
| 21 Sep | Aximage | | 35.9 | 35.9 | 34.7 | | | | | | 29.4 | 1.2 |
| 18–21 Sep | Intercampus | 1,005 | 38.9 | 38.9 | 35.7 | 7.3 | 4.4 | | | | 13.7 | 3.2 |
| 17–21 Sep | UCP–CESOP | 738 | 40.0 | 40.0 | 35.0 | 8.0 | 7.0 | | | | 10.0 | 5.0 |
| 20 Sep | Aximage | | 35.6 | 35.6 | 34.8 | | | | | | 29.6 | 0.8 |
| 18–20 Sep | Intercampus | 733 | 40.1 | 40.1 | 37.1 | 6.3 | 4.0 | | | | 12.5 | 3.0 |
| 19 Sep | Aximage | | 35.6 | 35.6 | 34.9 | | | | | | 29.5 | 0.7 |
| 16–19 Sep | UCP–CESOP | 613 | 40.0 | 40.0 | 35.0 | 8.0 | 7.0 | | | | 10.0 | 5.0 |
| 18 Sep | Aximage | | 35.5 | 35.5 | 35.1 | 8.4 | 5.7 | | | | 15.3 | 0.4 |
| 15–18 Sep | UCP–CESOP | 678 | 40.0 | 40.0 | 34.0 | 8.0 | 8.0 | | | | 10.0 | 6.0 |
| 14–17 Sep | UCP–CESOP | 647 | 41.0 | 41.0 | 34.0 | 7.0 | 8.0 | | | | 10.0 | 7.0 |
| 13–17 Sep | Aximage | 704 | 35.3 | 35.3 | 34.7 | 8.3 | 5.8 | | | | 16.0 | 0.6 |
| 11–16 Sep | Eurosondagem | 1,867 | 34.0 | 34.0 | 35.5 | 10.3 | 5.2 | | 1.8 | 2.2 | 11.0 | 1.5 |
| 4–7 Sep | Aximage | 602 | 38.9 | 38.9 | 33.3 | 8.5 | 4.6 | | 1.6 | 1.8 | 11.3 | 5.6 |
| 27 Aug–2 Sep | Eurosondagem | 1,040 | 35.0 | 35.0 | 36.0 | 10.4 | 4.6 | | 1.7 | 2.3 | 10.0 | 1.0 |
| 29 Jul–4 Aug | Eurosondagem | 1,030 | 34.8 | 34.8 | 36.3 | 10.0 | 5.0 | | 1.7 | 2.3 | 9.9 | 1.5 |
| 12–16 Jul | Aximage | 607 | 37.8 | 37.8 | 38.0 | 7.5 | 4.0 | | 1.3 | 1.4 | 10.0 | 0.2 |
| 2–7 Jul | Eurosondagem | 1,025 | 34.6 | 34.6 | 36.7 | 10.2 | 4.8 | | 1.9 | 2.5 | 9.3 | 2.1 |
| 26 Jun–4 Jul | Intercampus | 1,014 | 32.7 | 32.7 | 37.6 | 11.0 | 6.0 | 0.9 | 0.6 | 0.8 | 10.4 | 4.9 |
| 15–21 Jun | Pitagórica | 523 | 36.4 | 36.4 | 33.5 | 10.1 | 3.6 | | 1.3 | 1.6 | 13.5 | 2.9 |
| 13–16 Jun | UCP–CESOP | 1,048 | 38.0 | 38.0 | 37.0 | 10.0 | 8.0 | | | | 7.0 | 1.0 |
| 4–9 Jun | Eurosondagem | 1,030 | 33.3 | 33.3 | 36.9 | 10.5 | 4.5 | | 2.0 | 2.7 | 10.1 | 3.6 |
| 31 May–4 Jun | Aximage | 598 | 37.2 | 37.2 | 38.0 | 7.5 | 4.0 | | 1.2 | 2.1 | 10.0 | 0.8 |
| 7–12 May | Eurosondagem | 1,021 | 33.6 | 33.6 | 38.1 | 10.3 | 4.8 | | 1.8 | 2.5 | 8.9 | 4.5 |
| 7–10 May | Aximage | 605 | 37.2 | 37.2 | 37.3 | 7.7 | 4.2 | | 2.0 | 2.6 | 9.0 | 0.1 |
| 9–15 Apr | Eurosondagem | 1,025 | 26.7 | 8.0 | 37.5 | 10.2 | 4.3 | | 2.0 | 2.8 | 8.5 | 10.8 |
| 4–8 Apr | Aximage | 602 | 30.5 | 6.0 | 36.9 | 9.2 | 3.5 | | 1.7 | 3.8 | 8.4 | 6.4 |
| 5–10 Mar | Eurosondagem | 1,005 | 25.2 | 8.1 | 38.1 | 9.6 | 4.4 | | 2.1 | 3.0 | 9.5 | 12.9 |
| 3–6 Mar | Aximage | 600 | 28.9 | 6.1 | 36.1 | 10.7 | 4.0 | | 1.6 | 4.4 | 8.2 | 7.2 |
| 18–25 Feb | Eurosondagem | 1,515 | 35.0 | 35.0 | 37.5 | 9.6 | 4.2 | | 2.1 | 2.5 | 9.1 | 2.5 |
| 18–25 Feb | Eurosondagem | 1,515 | 27.8 | 7.7 | 36.5 | 10.0 | 4.4 | | 2.3 | 2.7 | 8.6 | 8.7 |
| 5–11 Feb | Eurosondagem | 1,015 | 26.7 | 6.9 | 38.1 | 9.0 | 4.0 | | 2.2 | 3.0 | 10.1 | 11.4 |
| 4–8 Feb | Aximage | 608 | 30.2 | 5.3 | 36.7 | 9.2 | 3.8 | | 2.5 | 5.2 | 7.1 | 6.5 |
| 8–14 Jan | Eurosondagem | 1,010 | 26.9 | 7.9 | 37.9 | 9.3 | 3.5 | | 2.0 | 2.5 | 10.0 | 11.0 |
| 9–12 Jan | Aximage | 601 | 30.9 | 4.7 | 36.9 | 7.7 | 3.5 | | 3.0 | 5.2 | 8.1 | 6.0 |
| 2015 |||||||||||||
| 4–10 Dec | Eurosondagem | 1,036 | 25.2 | 7.3 | 37.5 | 10.1 | 3.3 | | 1.7 | 2.2 | 12.7 | 12.3 |
| 1–4 Dec | Aximage | 607 | 31.0 | 5.1 | 37.4 | 7.6 | 5.2 | | 2.9 | 4.1 | 6.7 | 6.4 |
| 6–11 Nov | Eurosondagem | 1,022 | 25.3 | 7.7 | 36.9 | 10.4 | 3.6 | 1.0 | 1.5 | | 13.6 | 10.6 |
| 7–10 Nov | Aximage | 603 | 31.1 | 5.2 | 38.5 | 7.9 | 6.0 | | 2.1 | 2.1 | 7.1 | 7.4 |
| 11–13 Oct | UCP–CESOP | 1,064 | 28.0 | 4.0 | 45.0 | 10.0 | 4.0 | | | | 9.0 | 17.0 |
| 2–7 Oct | Eurosondagem | 1,021 | 26.2 | 8.0 | 34.8 | 10.5 | 4.0 | 2.1 | 1.6 | | 12.8 | 8.6 |
| 1–4 Oct | Aximage | 609 | 27.4 | 6.1 | 40.2 | 9.2 | 7.7 | | | 1.1 | 8.3 | 12.8 |
| 4–9 Sep | Eurosondagem | 1,011 | 28.0 | 7.5 | 33.0 | 10.7 | 4.3 | 3.3 | 1.7 | Did not exist | 11.5 | 5.0 |
| 31 Aug–3 Sep | Aximage | 602 | 28.6 | 8.4 | 30.9 | 11.9 | 5.7 | | | Did not exist | 14.5 | 2.3 |
| 31 Jul–6 Aug | Eurosondagem | 1,033 | 27.8 | 7.0 | 32.1 | 11.0 | 4.5 | 3.6 | 1.9 | Did not exist | 12.1 | 4.3 |
| 25–31 Jul | Pitagórica | 504 | 26.8 | 5.1 | 33.9 | 13.0 | 3.1 | 3.1 | | Did not exist | 15.0 | 7.1 |
| 25–31 Jul | Pitagórica | 504 | 28.1 | 6.9 | 30.0 | 12.7 | 4.2 | 3.5 | | Did not exist | 14.6 | 1.9 |
| 3–9 Jul | Eurosondagem | 1,014 | 27.5 | 6.6 | 32.5 | 11.1 | 4.9 | 4.0 | 2.0 | Did not exist | 11.4 | 5.0 |
| 4–7 Jul | Aximage | 593 | 27.2 | 8.3 | 31.0 | 10.7 | 6.9 | | | Did not exist | 15.9 | 3.8 |
| 2–5 Jun | Eurosondagem | 1,025 | 26.1 | 6.9 | 33.0 | 11.8 | 4.8 | 4.6 | 2.0 | Did not exist | 10.8 | 6.9 |
| 1–4 Jun | Aximage | 608 | 24.9 | 7.8 | 32.0 | 13.0 | 6.0 | | | Did not exist | 12.7 | 7.1 |
| 30 May–1 Jun | Pitagórica | 506 | 27.5 | 6.2 | 35.2 | 13.6 | 4.4 | 3.3 | | Did not exist | 9.8 | 7.7 |
| 30 May–1 Jun | Pitagórica | 506 | 28.0 | 6.3 | 30.6 | 14.4 | 4.8 | 3.7 | | Did not exist | 12.2 | 2.6 |
| 25 May 2014 | 2014 EP elections | 33.8% | 27.7 | 27.7 | 31.5 | 12.7 | 4.6 | 7.1 | 2.2 | Did not exist | 14.3 | 3.8 |
| 19–24 May | Intercampus | 4,004 | 28.7 | 2.4 | 29.1 | 11.4 | 5.4 | | | Did not exist | 23.0 | 0.4 |
| 14–22 May | Aximage | 1,507 | 29.0 | 7.3 | 36.2 | 10.3 | 6.5 | | | Did not exist | 10.7 | 7.2 |
| 1–7 May | Eurosondagem | 1,005 | 26.9 | 8.1 | 38.0 | 10.4 | 6.6 | | | Did not exist | 10.0 | 11.1 |
| 2–5 May | Aximage | 605 | 30.5 | 6.8 | 36.2 | 10.5 | 6.6 | | | Did not exist | 9.4 | 5.7 |
| 12–14 Apr | UCP–CESOP | 1,117 | 30.0 | 4.0 | 36.0 | 12.0 | 7.0 | | | Did not exist | 11.0 | 6.0 |
| 9–12 Apr | Aximage | 613 | 31.5 | 6.1 | 36.1 | 11.8 | 6.4 | | | Did not exist | 8.1 | 4.6 |
| 3–9 Apr | Eurosondagem | 1,011 | 25.2 | 8.1 | 37.3 | 10.9 | 7.5 | | | Did not exist | 11.0 | 12.1 |
| 25–29 Mar | Pitagórica | 506 | 27.6 | 7.6 | 39.0 | 10.3 | 6.9 | | | Did not exist | 8.6 | 11.4 |
| 6–12 Mar | Eurosondagem | 1,021 | 26.6 | 8.4 | 36.6 | 11.1 | 6.9 | | | Did not exist | 10.4 | 10.0 |
| 8–11 Mar | Aximage | 587 | 33.3 | 5.7 | 36.8 | 11.7 | 5.4 | | | Did not exist | 7.1 | 3.5 |
| 24 Feb–1 Mar | Pitagórica | 506 | 28.4 | 8.7 | 37.2 | 10.5 | 4.9 | | | Did not exist | 10.2 | 8.8 |
| 9–12 Feb | Aximage | 604 | 31.4 | 5.4 | 38.1 | 9.7 | 5.7 | | | Did not exist | 9.7 | 6.7 |
| 6–12 Feb | Eurosondagem | 1,025 | 25.6 | 7.7 | 36.9 | 10.5 | 7.0 | | | Did not exist | 12.3 | 11.3 |
| 20–24 Jan | Pitagórica | 506 | 25.8 | 7.8 | 37.8 | 11.4 | 6.6 | | Did not exist | Did not exist | 10.6 | 12.0 |
| 9–15 Jan | Eurosondagem | 1,010 | 25.0 | 8.0 | 37.5 | 10.4 | 6.6 | | Did not exist | Did not exist | 12.5 | 12.5 |
| 7–10 Jan | Aximage | 601 | 30.6 | 5.8 | 38.5 | 9.2 | 6.3 | | Did not exist | Did not exist | 9.6 | 7.9 |
| 2014 |||||||||||||
| 10–15 Dec | Pitagórica | 503 | 25.7 | 9.0 | 36.7 | 11.2 | 6.7 | Was not polled | Did not exist | Did not exist | 10.7 | 11.0 |
| 5–10 Dec | Eurosondagem | 1,035 | 26.5 | 8.5 | 36.5 | 10.0 | 6.5 | Was not polled | Did not exist | Did not exist | 12.0 | 10.0 |
| 6–9 Dec | Aximage | 609 | 29.6 | 8.3 | 36.4 | 9.7 | 6.3 | Was not polled | Did not exist | Did not exist | 9.7 | 6.8 |
| 19–21 Nov | Marktest | 800 | 25.6 | 1.5 | 35.6 | 17.2 | 6.5 | Was not polled | Did not exist | Did not exist | 13.6 | 10.0 |
| 6–9 Nov | Aximage | 602 | 28.4 | 9.4 | 36.9 | 10.3 | 6.8 | Was not polled | Did not exist | Did not exist | 8.2 | 8.5 |
| 30 Oct–5 Nov | Eurosondagem | 1,005 | 25.6 | 8.4 | 37.3 | 11.1 | 5.9 | Was not polled | Did not exist | Did not exist | 11.7 | 11.7 |
| 22–25 Oct | Marktest | 803 | 26.2 | 2.3 | 35.8 | 16.6 | 5.5 | Was not polled | Did not exist | Did not exist | 13.6 | 9.6 |
| 19–22 Oct | Aximage | 607 | 26.9 | 12.1 | 30.2 | 12.4 | 7.2 | Was not polled | Did not exist | Did not exist | 11.2 | 3.3 |
| 14–19 Oct | Pitagórica | 506 | 23.7 | 8.6 | 36.7 | 13.2 | 6.6 | Was not polled | Did not exist | Did not exist | 11.2 | 13.0 |
| 2–8 Oct | Eurosondagem | 1,010 | 26.9 | 8.6 | 36.5 | 12.1 | 5.9 | Was not polled | Did not exist | Did not exist | 10.0 | 9.6 |
| 29 Sep 2013 | 2013 local elections | 52.6% | 31.4 | 3.4 | 36.7 | 11.1 | 2.4 | 0.1 | Did not exist | Did not exist | 14.8 | 5.3 |
| 28–29 Sep | Intercampus | 1,000 | 27.0 | 4.0 | 39.0 | 11.0 | 7.0 | Was not polled | Did not exist | Did not exist | 12.0 | 12.0 |
| 26–29 Sep | Aximage | 609 | 30.2 | 10.3 | 34.5 | 10.4 | 5.6 | Was not polled | Did not exist | Did not exist | 9.0 | 4.3 |
| 17–19 Sep | Marktest | 801 | 28.5 | 2.5 | 36.6 | 11.5 | 7.3 | Was not polled | Did not exist | Did not exist | 13.6 | 8.1 |
| 5–11 Sep | Eurosondagem | 1,038 | 26.5 | 6.5 | 38.0 | 12.5 | 6.5 | Was not polled | Did not exist | Did not exist | 10.0 | 11.5 |
| 1–3 Sep | Aximage | 609 | 28.0 | 7.6 | 35.3 | 11.8 | 6.6 | Was not polled | Did not exist | Did not exist | 10.7 | 7.3 |
| 25–31 Jul | Eurosondagem | 1,020 | 24.4 | 7.7 | 37.4 | 12.5 | 7.5 | Was not polled | Did not exist | Did not exist | 10.5 | 13.0 |
| 27–29 Jul | Universidade Católica | 1,096 | 32.0 | 3.0 | 35.0 | 11.0 | 7.0 | Was not polled | Did not exist | Did not exist | 12.0 | 3.0 |
| 24–28 Jul | Pitagórica | 507 | 24.1 | 8.1 | 34.6 | 13.1 | 8.7 | Was not polled | Did not exist | Did not exist | 11.4 | 10.5 |
| 16–18 Jul | Marktest | 804 | 27.6 | 5.2 | 34.2 | 10.8 | 8.6 | Was not polled | Did not exist | Did not exist | 13.6 | 6.6 |
| 8–11 Jul | Aximage | 603 | 28.0 | 5.8 | 37.4 | 10.5 | 6.7 | Was not polled | Did not exist | Did not exist | 11.6 | 9.4 |
| 5–10 Jul | Eurosondagem | 1,007 | 25.0 | 8.0 | 37.0 | 12.0 | 8.0 | Was not polled | Did not exist | Did not exist | 10.0 | 12.0 |
| 28 Jun–2 Jul | Pitagórica | 503 | 23.7 | 9.1 | 33.9 | 13.2 | 8.9 | Was not polled | Did not exist | Did not exist | 11.2 | 10.2 |
| 4–7 Jun | Aximage | 599 | 23.2 | 9.4 | 35.5 | 11.5 | 8.4 | Was not polled | Did not exist | Did not exist | 12.0 | 12.3 |
| 30 May–4 Jun | Eurosondagem | 1,028 | 24.8 | 7.7 | 36.9 | 13.0 | 8.0 | Was not polled | Did not exist | Did not exist | 9.6 | 12.1 |
| 27–30 May | Marktest | 802 | 25.0 | 5.6 | 34.6 | 13.1 | 8.2 | Was not polled | Did not exist | Did not exist | 13.5 | 9.6 |
| 23–28 May | Pitagórica | 506 | 25.4 | 9.5 | 32.7 | 12.6 | 9.4 | Was not polled | Did not exist | Did not exist | 10.4 | 7.3 |
| 7–10 May | Aximage | 604 | 26.2 | 9.5 | 35.5 | 9.4 | 6.9 | Was not polled | Did not exist | Did not exist | 12.5 | 9.3 |
| 2–8 May | Eurosondagem | 1,009 | 25.9 | 8.4 | 36.0 | 12.1 | 8.8 | Was not polled | Did not exist | Did not exist | 8.8 | 10.1 |
| 17–20 Apr | Pitagórica | 503 | 26.9 | 12.0 | 28.6 | 12.8 | 8.7 | Was not polled | Did not exist | Did not exist | 11.0 | 1.7 |
| 5–10 Apr | Eurosondagem | 1,025 | 26.5 | 8.5 | 35.0 | 12.5 | 8.5 | Was not polled | Did not exist | Did not exist | 9.0 | 8.5 |
| 1–4 Apr | Aximage | 601 | 25.3 | 9.4 | 32.6 | 12.0 | 7.8 | Was not polled | Did not exist | Did not exist | 12.9 | 7.3 |
| 19–24 Mar | Pitagórica | 503 | 25.7 | 10.6 | 36.7 | 11.2 | 7.9 | Was not polled | Did not exist | Did not exist | 7.9 | 11.0 |
| 9–11 Mar | Universidade Católica | 949 | 28.0 | 5.0 | 31.0 | 12.0 | 8.0 | Was not polled | Did not exist | Did not exist | 16.0 | 3.0 |
| 4–6 Mar | Aximage | 607 | 25.1 | 12.1 | 31.6 | 12.2 | 7.1 | Was not polled | Did not exist | Did not exist | 11.9 | 6.5 |
| 28 Feb–5 Mar | Eurosondagem | 1,022 | 27.0 | 9.0 | 35.2 | 12.1 | 8.0 | Was not polled | Did not exist | Did not exist | 8.7 | 8.2 |
| 20–24 Feb | Pitagórica | 503 | 26.4 | 10.7 | 35.1 | 10.7 | 8.6 | Was not polled | Did not exist | Did not exist | 8.5 | 8.7 |
| 5–8 Feb | Aximage | 602 | 29.1 | 8.7 | 32.0 | 11.5 | 6.3 | Was not polled | Did not exist | Did not exist | 12.4 | 2.9 |
| 30 Jan–5 Feb | Eurosondagem | 1,011 | 27.6 | 9.5 | 34.1 | 11.6 | 8.4 | Was not polled | Did not exist | Did not exist | 8.8 | 6.5 |
| 22–25 Jan | Pitagórica | 504 | 28.6 | 10.2 | 33.8 | 12.0 | 8.0 | Was not polled | Did not exist | Did not exist | 7.4 | 5.2 |
| 15–21 Jan | Marktest | 803 | 27.9 | 5.2 | 32.6 | 12.4 | 13.3 | Was not polled | Did not exist | Did not exist | 8.6 | 4.7 |
| 6–9 Jan | Aximage | 603 | 26.3 | 10.3 | 32.9 | 11.8 | 7.4 | Was not polled | Did not exist | Did not exist | 11.3 | 6.6 |
| 3–8 Jan | Eurosondagem | 1,010 | 26.9 | 9.6 | 34.3 | 10.3 | 8.8 | Was not polled | Did not exist | Did not exist | 10.1 | 7.4 |
| 2013 |||||||||||||
| 13–18 Dec | Pitagórica | 511 | 29.0 | 11.4 | 34.6 | 11.2 | 8.4 | Was not polled | Did not exist | Did not exist | 5.4 | 5.6 |
| 5–11 Dec | Eurosondagem | 1,034 | 26.4 | 10.0 | 34.0 | 11.0 | 9.0 | Was not polled | Did not exist | Did not exist | 9.6 | 7.6 |
| 4–7 Dec | Aximage | 609 | 26.8 | 8.0 | 32.9 | 11.0 | 7.6 | Was not polled | Did not exist | Did not exist | 13.7 | 6.1 |
| 9–16 Nov | Pitagórica | 505 | 26.4 | 9.8 | 36.2 | 9.8 | 7.5 | Was not polled | Did not exist | Did not exist | 10.2 | 9.8 |
| 7–13 Nov | Eurosondagem | 1,033 | 26.9 | 10.1 | 35.0 | 10.0 | 9.5 | Was not polled | Did not exist | Did not exist | 8.5 | 8.1 |
| 30 Oct–6 Nov | Aximage | 602 | 26.3 | 7.9 | 32.1 | 9.6 | 7.5 | Was not polled | Did not exist | Did not exist | 16.6 | 5.8 |
| 8–13 Oct | Pitagórica | 503 | 29.5 | 8.3 | 34.1 | 9.1 | 7.2 | Was not polled | Did not exist | Did not exist | 11.8 | 4.6 |
| 4–9 Oct | Eurosondagem | 1,021 | 30.0 | 10.0 | 34.8 | 9.5 | 7.7 | Was not polled | Did not exist | Did not exist | 8.0 | 4.8 |
| 1–4 Oct | Aximage | 604 | 24.9 | 7.9 | 33.7 | 9.5 | 7.0 | Was not polled | Did not exist | Did not exist | 17.0 | 8.8 |
| 17–20 Sep | Marktest | 805 | 20.2 | 5.2 | 29.6 | 10.1 | 8.6 | Was not polled | Did not exist | Did not exist | 26.3 | 9.4 |
| 15–17 Sep | UCP–CESOP | 1,132 | 24.0 | 7.0 | 31.0 | 13.0 | 11.0 | Was not polled | Did not exist | Did not exist | 14.0 | 7.0 |
| 10–13 Sep | Eurosondagem | 1,037 | 33.0 | 10.3 | 33.7 | 9.3 | 7.0 | Was not polled | Did not exist | Did not exist | 6.7 | 0.7 |
| 3–6 Sep | Aximage | 600 | 33.3 | 7.1 | 35.4 | 7.7 | 5.3 | Was not polled | Did not exist | Did not exist | 11.2 | 2.1 |
| 9–14 Aug | Eurosondagem | 1,011 | 34.1 | 10.1 | 33.0 | 8.8 | 6.6 | Was not polled | Did not exist | Did not exist | 7.4 | 1.1 |
| 17–20 Jul | Marktest | 803 | 26.7 | 4.4 | 25.8 | 9.9 | 6.9 | Was not polled | Did not exist | Did not exist | 26.3 | 0.9 |
| 5–10 Jul | Eurosondagem | 1,036 | 34.6 | 10.1 | 32.5 | 8.7 | 6.9 | Was not polled | Did not exist | Did not exist | 7.2 | 2.1 |
| 2–4 Jul | Aximage | 600 | 35.0 | 7.9 | 30.8 | 7.8 | 5.3 | Was not polled | Did not exist | Did not exist | 13.2 | 4.2 |
| 19–22 Jun | Marktest | 800 | 31.3 | 2.8 | 29.2 | 9.5 | 5.4 | Was not polled | Did not exist | Did not exist | 21.8 | 2.1 |
| 7–12 Jun | Eurosondagem | 1,022 | 34.3 | 11.6 | 32.1 | 9.0 | 6.9 | Was not polled | Did not exist | Did not exist | 6.1 | 2.2 |
| 4–6 Jun | Aximage | 600 | 36.6 | 7.5 | 28.2 | 10.1 | 5.0 | Was not polled | Did not exist | Did not exist | 12.6 | 8.4 |
| 26–28 May | UCP–CESOP | 1,366 | 36.0 | 6.0 | 33.0 | 9.0 | 9.0 | Was not polled | Did not exist | Did not exist | 7.0 | 3.0 |
| 22–24 May | Marktest | 807 | 30.4 | 3.5 | 29.1 | 9.6 | 8.5 | Was not polled | Did not exist | Did not exist | 18.9 | 1.3 |
| 10–15 May | Eurosondagem | 1,011 | 34.8 | 11.6 | 31.2 | 8.8 | 6.0 | Was not polled | Did not exist | Did not exist | 7.6 | 3.6 |
| 2–5 May | Aximage | 600 | 36.3 | 6.2 | 28.9 | 9.7 | 4.3 | Was not polled | Did not exist | Did not exist | 14.6 | 7.4 |
| 17–21 Apr | Marktest | 810 | 31.4 | 3.6 | 25.4 | 10.2 | 7.8 | Was not polled | Did not exist | Did not exist | 21.6 | 6.0 |
| 11–17 Apr | Eurosondagem | 1,036 | 35.3 | 10.7 | 30.5 | 9.1 | 6.4 | Was not polled | Did not exist | Did not exist | 8.0 | 4.8 |
| 3–5 Apr | Aximage | 600 | 35.0 | 8.7 | 27.8 | 10.1 | 4.0 | Was not polled | Did not exist | Did not exist | 14.4 | 7.2 |
| 19–23 Mar | Marktest | 802 | 36.5 | 5.2 | 20.5 | 7.6 | 6.3 | Was not polled | Did not exist | Did not exist | 23.9 | 16.0 |
| 8–13 Mar | Eurosondagem | 1,021 | 36.0 | 12.0 | 29.6 | 8.5 | 6.9 | Was not polled | Did not exist | Did not exist | 7.0 | 6.4 |
| 5–7 Mar | Aximage | 600 | 36.2 | 6.5 | 31.4 | 9.2 | 2.9 | Was not polled | Did not exist | Did not exist | 13.8 | 4.8 |
| 14–22 Feb | Marktest | 800 | 30.2 | 3.9 | 25.9 | 9.3 | 6.0 | Was not polled | Did not exist | Did not exist | 24.7 | 4.3 |
| 2–7 Feb | Eurosondagem | 1,010 | 35.0 | 11.7 | 30.0 | 8.5 | 6.5 | Was not polled | Did not exist | Did not exist | 8.3 | 5.0 |
| 1–4 Feb | Aximage | 600 | 37.5 | 8.9 | 30.3 | 8.8 | 2.8 | Was not polled | Did not exist | Did not exist | 11.7 | 7.2 |
| 17–22 Jan | Marktest | 800 | 37.6 | 4.0 | 25.2 | 6.1 | 7.7 | Was not polled | Did not exist | Did not exist | 19.4 | 12.4 |
| 5–10 Jan | Eurosondagem | 1,064 | 36.4 | 12.1 | 30.3 | 7.7 | 6.4 | Was not polled | Did not exist | Did not exist | 7.1 | 6.1 |
| 3–6 Jan | Aximage | 600 | 37.9 | 9.3 | 30.0 | 10.7 | 2.5 | Was not polled | Did not exist | Did not exist | 9.6 | 7.9 |
| 2012 |||||||||||||
| 7–13 Dec | Eurosondagem | 1,033 | 36.0 | 12.5 | 30.0 | 8.8 | 6.4 | Was not polled | Did not exist | Did not exist | 6.3 | 6.0 |
| 5–8 Dec | Aximage | 600 | 39.5 | 9.1 | 27.7 | 11.3 | 3.3 | Was not polled | Did not exist | Did not exist | 9.1 | 11.8 |
| 15–19 Nov | Marktest | 804 | 45.4 | 5.0 | 19.7 | 7.9 | 4.1 | Was not polled | Did not exist | Did not exist | 17.9 | 25.7 |
| 10–15 Nov | Eurosondagem | 1,025 | 36.3 | 12.1 | 29.6 | 9.0 | 6.1 | Was not polled | Did not exist | Did not exist | 6.9 | 6.7 |
| 7–10 Nov | Aximage | 600 | 41.2 | 9.5 | 26.8 | 10.6 | 3.5 | Was not polled | Did not exist | Did not exist | 8.4 | 14.4 |
| 20–25 Oct | Eurosondagem | 1,032 | 36.9 | 12.5 | 29.2 | 8.8 | 6.3 | Was not polled | Did not exist | Did not exist | 6.3 | 7.7 |
| 18–22 Oct | Marktest | 809 | 41.6 | 5.3 | 19.7 | 10.5 | 4.2 | Was not polled | Did not exist | Did not exist | 18.7 | 21.9 |
| 3–5 Oct | Aximage | 600 | 41.1 | 10.2 | 26.0 | 7.6 | 5.0 | Was not polled | Did not exist | Did not exist | 10.1 | 15.1 |
| 22–27 Sep | Eurosondagem | 1,036 | 39.3 | 12.1 | 28.2 | 8.2 | 5.3 | Was not polled | Did not exist | Did not exist | 6.9 | 11.1 |
| 20–23 Sep | Marktest | 804 | 47.1 | 6.8 | 23.3 | 4.0 | 2.7 | Was not polled | Did not exist | Did not exist | 16.1 | 23.8 |
| 10–11 Sep | UCP–CESOP | 1,457 | 43.0 | 6.0 | 33.0 | 7.0 | 6.0 | Was not polled | Did not exist | Did not exist | 5.0 | 10.0 |
| 7–10 Sep | Aximage | 600 | 40.9 | 7.1 | 25.1 | 9.0 | 3.2 | Was not polled | Did not exist | Did not exist | 14.7 | 15.8 |
| 26–30 Aug | Eurosondagem | 1,025 | 39.6 | 12.5 | 26.9 | 8.4 | 5.5 | Was not polled | Did not exist | Did not exist | 7.1 | 12.7 |
| 14–19 Jul | Eurosondagem | 1,022 | 40.0 | 13.1 | 26.3 | 8.0 | 5.1 | Was not polled | Did not exist | Did not exist | 7.5 | 13.7 |
| 5–8 Jul | Aximage | 600 | 42.0 | 10.3 | 24.0 | 7.5 | 5.9 | Was not polled | Did not exist | Did not exist | 10.3 | 18.0 |
| 26–28 Jun | Eurosondagem | 1,010 | 40.8 | 13.6 | 25.0 | 7.7 | 4.8 | Was not polled | Did not exist | Did not exist | 8.1 | 15.8 |
| 5 Jun 2011 | 2011 legislative election | 58.0% | 38.7 | 11.7 | 28.0 | 7.9 | 5.2 | 0.4 | Did not exist | Did not exist | 7.7 | 10.6 |

## Seat projections

Opinion polls showing seat projections are displayed in the table below. The highest seat figures in each polling survey have their background shaded in the leading party's colour. In the instance that there is a tie, then no figure is shaded. 116 seats are required for an absolute majority in the Assembly of the Republic.
116 seats needed for majority :
| Date | Polling Firm | | | | | | | | | Others |
| 4 Oct 2015 | 2015 legislative election | 107 | 107 | 86 | 17 | 19 | 0 | 0 | 0 | 1 |
| 4 Oct | Eurosondagem | 100−108 | 100−108 | 84−90 | 15−18 | 16−19 | 0 | 0−1 | 0−1 | 0 |
| 4 Oct | Intercampus | 106−118 | 106−118 | 77−89 | 12−20 | 15−23 | 0 | 0−1 | 0 | 0−2 |
| 4 Oct | UCP–CESOP | 108−116 | 108−116 | 80−88 | 13−17 | 16−20 | 0 | 0−1 | 0 | 0 |
| Exit polls |||||||||||
| 24–29 Sep | Eurosondagem | 102−108 | 102−108 | 89−95 | 19−21 | 10−15 | 0 | 0 | 0 | 0−1 |
| 26–27 Sep | UCP–CESOP | 99−114 | 99−114 | 78−95 | 15−20 | 12−17 | 0 | 0−1 | 0 | 0−1 |
| 22–26 Sep | UCP–CESOP | 117 | 117 | 89 | 16 | 8 | 0 | 0 | 1 | 0 |
| 21–25 Sep | UCP–CESOP | 113 | 113 | 91 | 16 | 8 | 0 | 1 | 1 | 0 |
| 17–23 Sep | Eurosondagem | 100−103 | 100−103 | 97−102 | 20−22 | 5−7 | 0 | 1 | 0−2 | 0 |
| 11–16 Sep | Eurosondagem | 99−102 | 99−102 | 95−101 | 20−22 | 6−9 | 0 | 1 | 2 | 0 |
| 7–12 May | Eurosondagem | 97 | 97 | 103 | 21 | 6 | 0 | 1 | 2 | 0 |
| 18–25 Feb | Eurosondagem | 98−103 | 98−103 | 100−105 | 18−21 | 4 | 0 | 1−2 | 2 | 0 |
| 18–25 Feb | Eurosondagem | 78−87 | 13−17 | 99−105 | 20−21 | 4−6 | 0 | 2−3 | 2−3 | 0 |
| 2015 |||||||||||
| 5 Jun 2011 | 2011 legislative election | 108 | 24 | 74 | 16 | 8 | 0 | | | 0 |