10.22376/ijpbs.2019.10.1.p1-12 Volume 2 Issue 1 2011 (January - March) Antimicrobial activity of various extracts of roots (200mg/ml) of Ricinus communis were screened against pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Proteus vulgaris, Bacillus subtilis, Candida albicans and Aspergillus niger using well diffusion method. Aqueous extracts don't show any significant antimicrobial properties. The hexane and methanol extracts revealed maximum antimicrobial activity (p lessThan 0.0001). These findings established the potential of the roots of Ricinus communis as an effective antimicrobial agent. However, further studies are needed to evaluate active compounds and probable medicinal benefits in chemotherapy among humans.  Abhishek Mathur,Satish K. Verma,Sajad Yousuf,Santosh K. Singh,Gbks Prasad,V. K. Dua Ricinus communis, pathogenic microorganisms, methanol extracts, hexane extracts and chemotherapy. 545-548