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

128 entries were received for the competition following a submission period, from which ten acts were selected by a committee chaired by Head of the RTBF variety and entertainment department Pierre Meyer and announced on 12 December 1997.

[4][5] The winner, "Dis oui" performed by Mélanie Cohl, was selected solely by public televoting with the results being revealed by Belgium's six regions: four provinces in Wallonia with votes from Namur and Luxembourg being combined, a "Rest of Belgium" region made up of votes from Flanders, and Brussels.

[6][7][8] According to Eurovision rules, all nations with the exceptions of the eight countries which had obtained the lowest average number of points over the last five contests competed in the final on 9 May 1998.

[9][10] The day before the contest, Belgium was considered one of the favourites among bookmakers to win the competition, featuring alongside the entries from the United Kingdom, Sweden, Malta, and the Netherlands.