The 1978 Men's World Water Polo Championship was the third edition of the men's water polo tournament at the World Aquatics Championships, organised by the world governing body in aquatics, the FINA.

The tournament was held from 19 to 27 August 1978, and was incorporated into the 1978 World Aquatics Championships in West Berlin, West Germany.

First round results apply.

Alberto Alberani, Silvio Baracchini, Romeo Collina, Gianni De Magistris, Massimo Fondelli, Marco Galli, Sante Marsili, Alessandro Ghibellini, Paolo Ragosa, Mario Scotti-Galletta, Rolando Simeoni[1] Head coach: Gianni Lonzi

Alberto Alberani Silvio Baracchini Romeo Collina Gianni De Magistris Massimo Fondelli Marco Galli Alessandro Ghibellini Sante Marsili Paolo Ragosa Mario Scotti-Galletta Roldano SimeoniHead coach: Gianni Lonzi Gábor Csapó Tamás Faragó Szilveszter Fekete György Gerendás György Horkai György Kenéz István Magas Endre Molnár József Somossy Attila Sudár István Szívós Jr.Head coach: Dezső Gyarmati Siniša Belamarić Mirsad Galijaš Zoran Gopčević Boško Lozica Predrag Manojlović Zoran Mustur Damir Polić Zoran Roje Slobodan Trifunović Luka Vezilić Predrag VranešHead coach: Miro Ćirković