Abstract: In this study, eighty percent methanol and chloroform extracts of leaves and stems of Solanum nigrum were screened for in vitro anticancer activity using PC-3 human prostate cancer cell lines and Hela cervical cancer cells and cytotoxicity assays were performed using MTT assay and 3T3 NIH mouse embryo fibroblast cell line and CC-1, a rat Wistar hepatocyte cell line. All extracts in concentration 100 μg mL-1 showed anticancer activity in PC-3 and Hela and the highest percentage of growth inhibition obtained from stems methanol extracts on Hela 91.11% followed by leaves and stems methanol extracts (74.28 and 80.49, respectively) on PC-3. For cytotoxicity the result obtained indicate that all extracts had non-toxic effect on CC-I and 3T3 cell lines with IC50> 100 μg mL-1, except the leaves methanol extract showed the highest percentage of growth inhibition in 3T3 85.63 with IC50 17.37 μg mL-1. The results obtained indicate that Solanum nigrum leaves and stems methanol extracts have anticancer activity on prostate cancer, cervical cancer and have non-toxic effect on 3T3 and CC-1. This result supports the traditional use of Solanum nigrum for the treatment of cancer in different regions of the Sudan.