Freeze-dried fruits of two strawberry cultivars, Sweet Charlie and Carlsbad, and two blueberry cultivars, Tifblue and Premier, were sequentially extracted with hexane, 50% hexane/ethyl acetate, ethyl acetate, ethanol, and 80% acetone/water at ambient temperature. Solvents were then evaporated at 40 C. The extracts were tested against in vitro cultures of two aggressive cervical cancer cell lines (CaSki and SiHa) and two breast cancer cell lines with different requirements for estrogen (MCF-7 and T47-D). The metabolic activity of the cultures was assessed with MTS viability assay. The Ames assay for mutagenesis was used to evaluate the anticarcinogenic effects of phytochemicals with a 90% accuracy. Ethanol extracts from all four fruits strongly inhibited CaSki and SiHa cervical cancer cell lines and MCFF-7 and T47-D breast cancer cell lines. An unfractionated aqueous extract of raspberry and the ethanol extract of Premier blueberry significantly inhibited mutagenesis by both direct-acting and metabolically activated carcinogenesis.