The 1986 Mercedes Cup, was a men's tennis tournament played on outdoor clay courts and held at the Tennis Club Weissenhof in Stuttgart, West Germany that was part of the 1986 Grand Prix circuit. It was the ninth edition of the tournament and was held from 8 September until 14 September 1986. Third-seeded Martín Jaite won the singles title.
Martín Jaite defeated 
Jonas Svensson, 7–5, 6–2
Hans Gildemeister / 
Andrés Gómez defeated 
Mansour Bahrami / Diego Pérez, 6–4, 6–3