French-language broadcaster RTBF was in charge of the selection of the Belgian entry for the 1966 Contest, held at the RTBF studios in Brussels. Four songs were performed by Tonia and the winner was chosen by postcard voting. "Un peu de poivre, un peu de sel" emerged the winner by a margin of just over 1,000 votes.
On the night of the final Tonia performed 3rd in the running order, following Denmark and preceding Luxembourg. Each national jury awarded 5-3-1 points to their top three songs, and at the close of the voting "Un peu de poivre, un peu de sel" had received 14 points (5 from Germany and the Netherlands, 3 from Portugal and 1 from Sweden), placing Belgium joint 4th (with Ireland) of the 18 competing entries. This was Belgium's highest Eurovision finish to date, and would remain so until Jean Vallée's second place in 1978. The Belgian jury awarded its 5 points to contest winners Austria.