 Paul MeurisseStanilas Octave Seminario aka 'SOS', détective | Stanilas Octave Seminario aka 'SOS', détective |
 Micheline FranceyMuriel Pescara, the daughter | Muriel Pescara, the daughter |
 Gilbert GilCharles Pescara, the son | Charles Pescara, the son |
 Pierre RenoirDoctor Gérard Pescara, the father | Doctor Gérard Pescara, the father |
 Jean TissierGuillaume | Guillaume |
 Pierre-LouisPaul Wantz | Paul Wantz |
 Junie AstorHélène Tassin, nurse | Hélène Tassin, nurse |
 Jean DebucourtDoctor Vermeulen | Doctor Vermeulen |
 Jean BrochardInvestigating judge | Investigating judge |
 Mady BerryBrigitte Tassin | Brigitte Tassin |
 Pierre PalauDoorman | Doorman |
 Arthur DevèreLock keeper | Lock keeper |
 Marcel PérèsRoad mender | Road mender |
 SinoëlGardener | Gardener |
 Georges BeverBaptiste, clerk | Baptiste, clerk |
 Madeleine SuffelHotel boss | Hotel boss |
| MMichel SeldowIllusionist Pablo | Illusionist Pablo |
 Marc Arian(uncredited) | (uncredited) |
 Léon Arvel(uncredited) | (uncredited) |
 Alfred BaillouMan (uncredited) | Man (uncredited) |
 Rivers Cadet(uncredited) | (uncredited) |
 Marcel Charvey(uncredited) | (uncredited) |
| RRaymond Destac(uncredited) | (uncredited) |
 Pierre Duncan(uncredited) | (uncredited) |
| CCécile Eddy(uncredited) | (uncredited) |
| HHenry GerrarConcierge (uncredited) | Concierge (uncredited) |
 Claire GérardConcierge (uncredited) | Concierge (uncredited) |
| CColette Mareuil(uncredited) | (uncredited) |
 Pierre Moncorbier(uncredited) | (uncredited) |
 Geneviève MorelPescara cook (uncredited) | Pescara cook (uncredited) |
