Almirao qualified for the women's 400 metres at the 2004 Summer Olympics in Athens, by winning the gold medal from the Ibero-American Championships in Huelva, Spain. She finished fifth in the second heat of the event by six hundredths of a second (0.06) behind Jamaica's Nadia Davy, with a time of 52.10 seconds. Almirao eventually joined the national sprint team for the women's 4 × 400 m relay, along with her compatriots Josiane Tito, Lucimar Teodoro, and Geisa Coutinho. She and her team placed sixth on the second heat of the relay, for a seasonal best time of 3:28.43.