The feeding of 0+ smelt (Osmerus eperlanus) was studied in Lake Peipsi (Estonia/Russia). Smelt fed mainly on zooplankton, especially on cladocerans and copepods, and not on rotifers. The dominant taxa in smelt food were Daphnia sp., Bosmina longirostris, Bosmina coregoni, Chydorus sphaericus, Eudiaptomus sp., Mesocyclops spp., and cyclopoid copepods. Copepods constituted a greater percentage of the food of smelt at the beginning of July; from August cladocerans dominated. Size-selectivity was variable: in July and August smelt selected larger-bodied species, while from September onwards both large-and small-bodied species were eaten.