The 1986 Donnay Indoor Championships was a men's tennis tournament played on indoor carpet courts[3] at the Forest National in Brussels, Belgium the event was part of the 1986 Nabisco Grand Prix.

It was the sixth edition of the tournament and was held from 13 March until 23 March 1986.

First-seeded Mats Wilander won the singles title.

[3][4] Mats Wilander defeated Broderick Dyke, 6–2, 6–3 Boris Becker / Slobodan Živojinović defeated John Fitzgerald / Tomáš Šmíd, 7–6, 7–5