The present study was designed to evaluate in vitro anti-proliferative potential of extracts from four Indian medicinal plants, namely Anogeissus latifolia, Terminalia bellerica, Acacia catechu and Moringa oleiferna. Their cytotoxicity was tested in nine human cancer cell lines, including cancers of lung (A549), prostate (PC-3), breast (T47D and MCF-7), colon (HCT-16 and Colo-205) and leukemia (THP-1, HL-60 and K562) by using SRB and MTT assays. The findings showed that the selected plant extracts inhibited the cell proliferation of nine human cancer cell lines in a concentration dependent manner. The extracts inhibited cell viability of leukemia HL-60 and K562 cells by blocking G0/G1 phase of the cell cycle. Interestingly, A. catechu extract at 100 μg/mL induced G2/M arrest in K562 cells. DNA fragmentation analysis displayed the appearance of a smear pattern of cell necrosis upon agarose gel electrophoresis after incubation of HL-60 cells with these extracts for 24 h.