A survey is presented of the Dutch sciomyzid flies. From data of diverse collections it can be concluded that at least fifty species occur in the Netherlands. Six of them are new for the Dutch sciomyzid fauna: Pelidnoptera fumipennis, Pherbellia czernyi, Pherbina intermedia, Psacadina zernyi, Dichetophora finlandica and Limnia paludicola. The main biological features, especially of the larvae, are summarized. Most common in Holland are the air-breathing, free-living overt predators of non-operculate snails, but also parasitoids of terrestrial snails can be found. Some remarks are made on further research, among others in relation to the possible value of the sciomyzid larvae as biological control agents of those snails, which transmit diseases. Met dank aan Pjotr Oosterbroek en Ben Brugge voor hun hulp bij dit onderzoek.