Conventional treatment of raw water for the municipal supply of drinking water may include chemical addition, coagulation, flocculation, sedimentation, filtration and disinfection, usually with chlorine. The reason for a larger use of membrane filtration systems, such as microfiltration and ultrafiltration, in this field, is mainly due for example to the ability of the membrane to remove pathogenic microorganisms as well as to control the disinfection by-products (DBPs) precursor. In this paper the use of microfiltration ceramic membranes for the treatment of raw water drawn from a lake located near Genoa is studied. The behaviour of permeate flux as a function of operating variables such as temperature, transmembrane pressure, and test duration is analysed. Membrane retention towards particles, microorganisms, algae and DBPs precursor is also investigated.