Portugal was represented at the Eurovision Song Contest 1965 with the song "", composed by Carlos Nóbrega e Sousa, with lyrics by Jerónimo Bragança, and performed by Simone de Oliveira. The Portuguese participating broadcaster, (RTP), selected its entry at the 1965.
(RTP) held the 1965 on 6 February 1965 at 21:55 UTC in its Lumiar studios in Lisbon, hosted by Henrique Mendes. Eight songs took part in the final. Fernando de Carvalho conducted orchestra for all the songs. The winning song was chosen by a distrital jury, composed by three members, each had 5 votes to be distributed among the songs it intended to award, making a total of 15 votes per district.
On the night of the final Oliveira performed 12th in the running order, following and preceding . Each national jury awarded 5-3-1 to their top three songs, and at the close "Sol de inverno" had picked up only 1 point (from Monaco), placing Portugal joint 13th (with ) of the 18 entries. The Portuguese jury awarded its 5 points to .
The orchestra during the Portuguese entry was conducted by Fernando de Carvalho.