| Heat 3 17:00 | | time | | gap | L | Rk | | 1. Gyorgy Mitro |  Hungary | 19:28.0 | | | 7 | 1. | | 2. Ferenc Voros | Hungary | 20:07.0 | | +39.0s | 5 | 2. | | 4. Miloslav Bartusek |  Czechoslovakia | 20:18.7 | | +50.7s | 1 | 3. | | 5. Jack Hale |  Great Britain | 20:45.9 | | +1:17.9 | 2 | 4. | | 7. Zmaj Defillipis |  Yugoslavia | 20:51.0 | | +1:23.0 | 3 | 5. | | 10.Bror Ebbe Anderson |  Sweden | 21:05.6 | | +1:37.6 | 4 | 6. | | -. Olle Johansson | Sweden | DNS | | | 6 | |
| Heat 2 16:30 | | time | | gap | L | Rk | | 3. Marijan Stipetic | Yugoslavia | 20:08.5 | | +40.5s | 5 | 1. | | 8. Rinus van Daatselaar |  Netherlands | 20:59.1 | | +1:31.1 | 2 | 2. | | 9. Claude Fourcade |  France | 20:21.4 | | +1:53.4 | 3 | 3. | | 14.Vittorio Manetti |  Italy | 21:36.4 | | +2:08.4 | 4 | 4. | | -. Emile Vial | France | DNF | | | 1 | |
| Heat 1 10:30 | | time | | gap | L | Rk | | 6. Joseph Reynders |  Belgium | 20:47.2 | | +1:19.2 | 3 | 1. | | 11.Harry Bates | Great Britain | 21:10.3 | | +1:42.3 | 1 | 2. | | 12.Bror Labart |  Finland | 21:13.9 | | +1:45.9 | 5 | 3. | | 13.Giancarlo Paulon | Italy | 21:20.4 | | +1:52.4 | 4 | 4. | | -. Jose da Silva |  Portugal | DNS | | | 2 | |
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| No Final Heat. Swimmers were put in 3 heats. Best were included in Heat 3. | | 2 competitors from nation were allowed participate. |
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