The 1978 Monte Carlo Open was a men's tennis tournament played on outdoor clay courts at the Monte Carlo Country Club in Monte Carlo, Monaco . The tournament was part of the WCT Tour, which was incorporated into the 1978 Colgate-Palmolive Grand Prix circuit. It was the 72nd edition of the event and was held from April 10 through April 16, 1978. Raúl Ramírez, the no. 5 seed, won the singles title.
Raúl Ramírez defeated Tomáš Šmíd 6–3, 6–3, 6–4
Peter Fleming / Tomáš Šmíd defeated Jaime Fillol / Ilie Năstase 6–4, 7–5