Cytotoxicity activities of the crude ethanol extracts from Chamaecostus subsessilis and Chamaecostus cuspidatus and the fractions obtained by liquid-liquid partition were observed when these species were assayed against a panel of six human cancer cell lineages (HL60, Jurkat, MDA-MB231, MCF-7, HCT, THP-1) and normal (Vero) cells using the MTT colorimetric assay. The cytotoxic effects in the HL60, Jurkat and THP-1 lineages were mediated via an apoptotic mechanism when treated with crude ethanol extracts from these species. The presence of flavonoids, terpenoids and saponins in fractions from both species was observed in the preliminary phytochemical study. These results provide scientific support for the study of the Costaceae family and show that C. cuspidatus and C. subsessilis are potential sources of compounds with anticancer activities.