Abstract: Diabetes and cancer are common diseases that tremendously affect health worldwide.Epidemiologic evidence suggests that the incidence and mortality risks of several types of cancer such as pancreatic, liver, colorectal, kidney, bladder, female breast, and endometrial cancer are increased among diabetics.The association between diabetes and cancer may be due to direct and indirect mechanisms.Direct mechanisms include hyperinsulinemia, hyperglycemia, and chronic inflammation.Potential risk factors include aging, sex, race, obesity, diet, physical activity, smoking, and alcohol intake.This article reviews the evidence of the association between diabetes and cancer.