This paper reports on the larvae development of the flat oyster, Ostrea edulis (Linnaeus, 1758), from veliger to pediveliger stage. Adult oysters were induced to spawn by thermal stimulation and large amounts of veliger larvae were obtained for study. Veliger larvae were cultured in 180-1 bins at a density of 3 larvae/ml. Larvae, reared at 20 +/- 2 degrees C and fed 8-200 x 10(3) cells/ml of Isochrysis galbana, reached pediveliger larvae in 17 days. Shell length and width at the beginning of the pediveliger stage were 254 and 233 mu m, respectively. Survival rate from veliger to viable pediveliger stage was 15.5%.