Colon cancer is the third most common cancer in men and second in women. Cancer treatments include chemotherapy, but some chemotheraphy drugs are resistant. Vernonia amygdalina Del. is one of the most widely reported plant that can inhibit the growth of various cancer cell lines. This study aims to examine the anticancer activity of Vernonia amygdalina Del. extract on WiDr colon cancer cell line. This research is an experimental research in vitro using posttest only control group design. Research subjects are WiDr cells. The research method starts from preparation and characterization of simplicia, gradual maceration of Vernonia amygdalina Del. using n-hexane, ethyl acetate, and ethanol, phytochemical analysis of each extracts, cytotoxicity assay on WiDr cells using MTT (Microculture Tetrazolium Technique) assay. Ethyl acetate extract of Vernonia amygdalina Del. has the lowest IC 50 value in cytotoxicity assay results, indicate that ethyl acetate extract has very strong citotoxic activity on WiDr cells. Further studies are to analysis the mechanisms of ethyl acetate extracts in induce apoptosis, inhibition of cell cycle, and to observe the protein expression associated with it.