Belgium was represented by Lize Marke, with the song '"Als het weer lente is", at the 1965 Eurovision Song Contest, which took place on 20 March in Naples. Marke was chosen internally to be the Belgian representative, and the song was chosen in the national final on 13 February. Marke had previously finished second in the Belgian preselection in 1963.
There was a minor controversy after the selection when it came to light that "Als het weer lente is" had previously been performed on TV (ironically by the following year's Belgian representative Tonia), but after some deliberation broadcaster BRT decided not to disqualify the song, as none of the rules of the European Broadcasting Union in effect at the time regarding song selection had been broken.
The final was hosted by Nand Baert at the Amerikaans Theater in Brussels. Six songs were performed by Marke and the winner was chosen by a 20-member jury consisting of 10 "experts" and 10 members of the public. It is not known how the songs were scored, nor whether the votes of the experts and the public carried equal weight.
On the night of the final Marke performed 8th in the running order, following Norway and preceding Monaco. Voting was by each national jury awarding 5, 3 and 1 points to its three favourite songs. At the close of the voting "Als het weer lente is" was one of four songs (along with the entries from Finland, Germany and Spain) which had failed to register a single point. This was the third time that Belgium had found itself at the foot of the Eurovision scoreboard, and the second (and to date last) time the country had finished with the infamous nul-points.
The Belgian jury vote was unique under this system, as only two songs had received any votes at all from the 10 jury members. Under the rules then in effect, this meant that they awarded 6 points (rather than the apparent maximum 5) to the United Kingdom and 3 points to Italy.