Although its mechanism of action on cancer cells not well understood, Metformin (Met) is widely used nowadays to improve the anticancer activity of some drugs. Metformin has also been shown to decrease the growth of breast cancer cells and pancreatic cancer in hamsters and delays other types of tumors. The aim of this study was to compare the effects of Cisplatin (Cis) alone and Metformin alone on colon cancer cell line SW480. The results showed that the effect of Metformin on cell proliferation is concentration-dependent. Metformin enhances the proliferation and attachment of colon cancer at lower concentrations. Results showed a significant decrease in cell proliferation and attachment of colon cancer cells after Cisplatin treatment.Results of this study revealed that Cisplatin treatment decreased both proliferation and cell adhesion to the matrix. Combination therapy (Met+Cis) showed promising synergism and enhancement of anticancer activity of Cisplatin on colon cancer cells. We are strongly recommended more investigations to be more specific for using Metformin as general anticancer.