In recent years an increasing attention is focused on the potential effects of drugs on cancer incidence and/or cancer survival. Many medications of common use, developed for a variety of medical non-cancer situations, have been found to have potential anti- cancer effects. In this article, we performed an overview of the literature evidence for several commonly used non-cancer medications, such as aspirin, beta-blockers, metformin and other anti- diabetics, cardiac glycosides, anticoagulant heparin, statins, psychotropic drugs, vitamins, calcium and estrogens which have been shown to have anticancer effects, in observational and experimental studies. A huge amount of data supports the idea that a few of these commonly used medicines could decrease cancer death-rate, particularly aspirin, statins and metformin, crosswise different types of cancer. To date, no mature data are available from randomized and prospective trials; perhaps, the results of some studies underway will allow us to answer some questions on the possible use of these drugs in our clinical practice in primary and secondary prevention, or even in adjuvant setting.