Extracts from propolis have been investigated for cytostatic activity in vitro, by method of tissue culture on human KB and HeLa cell lines. Diethyl ether extract (DEEP) sowed the greatest activity and therefore it was further fractionated. Secondary DEEP fractions obtained by extraction with BuOH (ED50 = 2.6 micrograms/ml) and AcOEt (ED50 = 3.3 micrograms/ml) have been qualified to further in vivo studies.