The Belgian participating broadcaster, Walloon Radio-télévision belge de la Communauté française (RTBF), selected its entry through a national final.

Walloon broadcaster Radio-télévision belge de la Communauté française (RTBF) had the turn to participate in the Eurovision Song Contest 1978 representing Belgium.

The jury were then given two hours to vote, and the winner was announced in a short programme at 22:35 CET.

[2] On the evening of the final Vallée performed 10th in the running order, following Switzerland and preceding the Netherlands.

This ranked Belgium second of the 20 competing countries, the highest position achieved by a Belgian entry in Eurovision to that date, which has since only been bettered by Sandra Kim's 1986 victory and matched by Urban Trad in 2003.