Alcoholic extracts of four Indian medicinal plants Kaempferia galanga (Zingiberacae) Linn. Clerodendrum viscosum (Verbenaceae) Linn., Jatropha curcus (Euphorbiaceae) Linn. and Lens culinaris (Fabaceae) Linn. were subjected to preliminary screening for their antitumor activity. Acute toxicity studies in mice revealed that all the ethanolic extracts were safe up to a dose level of 500, 1000, 2000 mg kg-1 body weight. Preliminary short term anticancer screening, by brine shrimp lethality test, potato disc inhibition and DLA cell line assay, proved that K. galanga, exhibited significant antitumor activity and it was therefore, selected as a candidate plant for more detailed phytochemical and mechanistic studies. Brine shrimp lethality assay revealed that K. galanga extract inhibited tumor development at a lower concentration LC50 = 684.2 μg mL-1 as compared to 901, 866 and 5436 μg mL-1 for the extracts of C. viscosum, J. curcus and L. culnaris, respectively. Alcoholic extract of K. galanga significantly (p<0.001) inhibited Agrobacterium induced tumors in potato discs with average tumor count of 15, 11, 8.0, 6.0 and 4.8 at concentrations of 10, 20, 30, 40 and 50 μg mL-1, respectively. K. galanga extract regress tumors equipotently to vincristine in Dalton Lymphoma Ascitic (DLA) cell tumor bearing mice. There was a statistically significant (p<0.001) higher mean increase in Percentage Life Span (ILS) in rats treated with K. galanga extract 73.27±10.51 with median value of 69.85% as compared to Vincristine group 53.84±11.94 with median 54.25%. Preliminary phytochemical tests of the candidate plant K. galanga indicated the presence of flavonoids, suggesting a prominent role for them in anticancer activity.