The castor oil plant is a fast-growing, suckering perennial shrub or occasionally a soft wooded small tree up to 6 meter or more, but it is not hardy in nature. Two varieties of this plant are known a perennial bushy plant with large fruits and large red seeds which yields about 40 P.C of oil. A much smaller annual shrub with small grey (white) seeds having brown spots and yielding 37% of oil. It is one of the most important fruits worldwide because the castor oil obtained from the seed of the plant is still widely used traditionally and herbally as a medicine. Recently the crude whole fruits with seeds had shown that potential biological activities against various infectious diseases. The objectives of the present work was to search antimicrobial activities. Based on this, a new series of constituents had been planned to extract by methanol (E1), ethanol (E2), acetone (E3), chloroform (E4) and ether (E5) from castor fruit-seeds. The in-vitro antimicrobial activity of various extracts of fruit-seeds of R. communis were carried out by using agar diffusion method using bacterial cultures Staphylococcus aureus (ATCC 9144), Bacillus subtilis (ATCC 6633), Pseudomonas aeruginosa (ATCC 27853, ) Escherichia coli (ATCC 25922) and fungal cultures Aspergillus niger (ATCC 9029), Aspergillus flavus (ATCC 204304), Candida albicans (ATCC 10231). By observing it was found that most of the extracts executed moderate to good antimicrobial activity against the tested micro-organisms. The extracts were active against all the tested microorganism for anti bacterial activity with range of MIC values for S.aureus (MIC: 15-39 µg /ml ), E.coli ( MIC: 16-38 µg /ml), P.aeruginosa ( MIC:15-39 µg /ml) and B.subtilis (14-39 µg /ml). The extracts were active against all the tested microorganism for anti fungal activity with the range of MIC values for A.niger (MIC :17-39 µg/ml),A.flavus (18-37 µg/ml) and C.albicans (16-35 µg/ml).