Portugal was represented at the Eurovision Song Contest 1966 with the song "", written by Carlos Canelhas, and performed by Madalena Iglésias. The Portuguese participating broadcaster, (RTP), selected its entry at the 1966.
(RTP) held the 1966 on 15 January 1966 at 22:00 UTC at Tóbis studios in Lisbon, hosted by Maria Fernanda and Henrique Mendes. Eight songs took part in the final. Jorge Costa Pinto conducted 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 Iglésias performed 8th in the running order, following and preceding . At the close of the voting the song had received 6 points, coming 13th in the field of 18 competing countries. The Portuguese jury awarded its 5 points to .
The orchestra during the Portuguese entry was conducted by Jorge Costa Pinto.