Silver nanoparticles (AgNPs) synthesized using aqueous leaf extract of Ricinus communis (Castor plant) were examined for their antimicrobial and anticancer activities. Antimicrobial activity against the Escherichia coli, Pseudomonas aeruginosa (Gram negative), Bacillus subtilis, Staphylococcus aureus (Gram positive) and Rhodobactor sphaeroides (Purple bacteria) and anticancer activity was examined against MCF-7 cells (human breast cancer cell line). The AgNPs were characterized by the UV-Visible spectroscopy, Scanning electron microscopy (SEM),Energy-disruptive X-ray spectroscopy (EDX) and Transmission electron microscopy (TEM). Antimicrobial and anticancer activities of AgNPs were studied well diffusion method and SRB assay. Synthesis of AgNPs was confirmed by analyzing the spectra at 445 nm using UV-vis spectrophotometer. The TEM and SEM analysis showed an average 8.96 nm size aggregates of spherical shaped AgNPs. EDX showed the complete chemical composition of synthesized AgNPs. The maximum zone of inhibition was observed in R. sphaeroides (13, 14, 15, and 16 mm) than the other bacterial species (E. coli, P. aeruginosa, B. subtilis, and S.). The AgNPs tested for anticancer activity showed the high toxicity towards the MCF-7 cells (human breast cancer cell line) (LC50 14.95 μg/mL). We can conclude that, it is a novel, cost effective, ecofriendly,green approach towards antimicrobial and anticancerous activities. In future, R. communis synthesized AgNPs could be used in pharmaceutical field to develop antimicrobial and anticancerous products