Abstract: Seed germination, seedling growth and callus induction was compared between two varieties of Ricinus communis L. Callus cultures were initiated from roots, hypocotyls and cotyledonary leaves of the aseptically germinated seedlings on MS medium supplemented with 0.8% agar, 3% sucrose and various combinations of auxins and cytokinins. Seedling growth development and callus growth rate of large-seeded variety (var. major) was higher than that of small-seeded variety (var. minor). However, ricinine content was higher (6.59-7.97 μg g-1 FW) in callus cultures initiated from var. minor than that accumulated in var. major (2.44-4.35 μg g-1 FW). Broad spectrum antibacterial activity was recorded from ethanol and ether extracts of callus cultures of both varieties of R. communis L. against gram-positive and Gram-negative bacteria. Callus cultures subcultured for 3-6 subcultures diffused their antibacterial compounds into agar media during growth development. None of the callus extracts showed activity against Candida albicans. Bioautographic TLC analysis revealed that the antibacterial activity of var. major was due to quercetin and ricinine, while activity of var. minor was due to quercetin, kaempferol and ricinine. In vitro anthelmintic activity against Mesocestoides corti and Taenia crassiceps was recorded from callus cultures initiated from R. communis L. var. major only. Percent mortality of both organisms was high (93-95%) after incubation for 48 h in the presence of 20 μL root extracts of variety major.