# 1986 Milan Indoor – Singles

John McEnroe was the defending champion, but did not participate this year.
Ivan Lendl won the tournament, beating Joakim Nyström in the final, 6–2, 6–2, 6–4.

## Seeds

* Ivan Lendl (champion)
* Joakim Nyström (final)
* Anders Järryd (semifinals)
* Miloslav Mečíř (semifinals)
* Henrik Sundström (first round)
* Tomáš Šmíd (first round)
* Jakob Hlasek (quarterfinals)
* Jan Gunnarsson (second round)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 1 | Ivan Lendl | 7 | 6 | | | | | |
| 4 | Miloslav Mečíř | 5 | 4 | | | | | |
| 4 | Miloslav Mečíř | 5 | 4 | 1 | Ivan Lendl | 6 | 6 | 6 |
| | | | | 2 | Joakim Nyström | 2 | 2 | 4 |
| 3 | Anders Järryd | 3 | 6 | 2 | Joakim Nyström | 2 | 2 | 4 |
| 2 | Joakim Nyström | 6 | 7 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | I Lendl | 6 | 6 | | | | | | | | | | | | | | |
| | J Aguilera | 3 | 1 | | 1 | I Lendl | 6 | 7 | | | | | | | | | |
| Q | M Ostoja | 6 | 6 | 6 | Q | M Ostoja | 1 | 5 | | | | | | | | | |
| | J López-Maeso | 4 | 7 | 2 | | | | | | 1 | I Lendl | 6 | 6 | | | | |
| Q | M Fioroni | 6 | 4 | 4 | | | | | | 7 | J Hlasek | 3 | 4 | | | | |
| | M Vajda | 4 | 6 | 6 | | M Vajda | 6 | 3 | | | | | | | | | |
| Q | T Högstedt | 4 | 2 | | 7 | J Hlasek | 7 | 6 | | | | | | | | | |
| 7 | J Hlasek | 6 | 6 | | | | | | | | | | | 1 | I Lendl | 7 | 6 |
| 4 | M Mečíř | 2 | 7 | 6 | | | | | | | | | | 4 | M Mečíř | 5 | 4 |
| WC | P Canè | 6 | 6 | 3 | 4 | M Mečíř | 6 | 6 | | | | | | | | | |
| | S Perkiss | 6 | 3 | 3 | | J Fitzgerald | 2 | 4 | | | | | | | | | |
| | J Fitzgerald | 3 | 6 | 6 | | | | | | 4 | M Mečíř | 6 | 6 | | | | |
| | F Cancellotti | 3 | 6 | 2 | | | | | | | S Casal | 1 | 2 | | | | |
| | S Casal | 6 | 4 | 6 | | S Casal | 6 | 3 | 7 | | | | | | | | |
| | R Simpson | 4 | 7 | 6 | | R Simpson | 2 | 6 | 6 | | | | | | | | |
| 5 | H Sundström | 6 | 6 | 2 | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | T Šmíd | 2 | 3 | | | | | | | | | | | | | | |
| | A Mansdorf | 6 | 6 | | | A Mansdorf | 6 | 6 | | | | | | | | | |
| Q | S Glickstein | 4 | 2 | | | C Steyn | 1 | 1 | | | | | | | | | |
| | C Steyn | 6 | 6 | | | | | | | A Mansdorf | 6 | 5 | | | | | |
| | C Panatta | 1 | 6 | | | | | | 3 | A Järryd | 7 | 7 | | | | | |
| | E Sánchez | 6 | 7 | | | E Sánchez | 2 | 4 | | | | | | | | | |
| | M Edmondson | 4 | 4 | | 3 | A Järryd | 6 | 6 | | | | | | | | | |
| 3 | A Järryd | 6 | 6 | | | | | | | | | | | 3 | A Järryd | 3 | 6 |
| 8 | J Gunnarsson | 6 | 6 | | | | | | | | | | | 2 | J Nyström | 6 | 7 |
| | M Flur | 4 | 4 | | 8 | J Gunnarsson | 0 | 2 | | | | | | | | | |
| | V Gerulaitis | 6 | 6 | 5 | | B Green | 6 | 6 | | | | | | | | | |
| | B Green | 7 | 3 | 7 | | | | | | B Green | 1 | 6 | 2 | | | | |
| | F Segărceanu | 3 | 4 | | | | | | 2 | J Nyström | 6 | 4 | 6 | | | | |
| | P Složil | 6 | 6 | | | P Složil | 4 | 2 | | | | | | | | | |
| | J Svensson | 3 | 2 | | 2 | J Nyström | 6 | 6 | | | | | | | | | |
| 2 | J Nyström | 6 | 6 | | | | | | | | | | | | | | |