AbstractWith the ever‐emerging concerns of patient safety during medical care, the search for treatments as safe as possible is a priority, especially when focusing on cancer treatment of which therapies often go hand in hand with severe side effects. Oncolytic virotherapy is an emerging treatment for cancer that is promising in both safety and efficacy. Many currently ongoing clinical trials demonstrate the growing interest in this field. To conduct clinical trials, preclinical studies are mandatory; however, there are not many reviews of toxicology studies on oncolytic virus therapies. This article summarizes the preclinical toxicology studies of the most well studied oncolytic viruses, including Oncorine, Talimogene laherparepvec, Cavatak, ONYX‐015, teserpaturev and Rigvir, a non‐pathogenic ECHO‐7 virus. It is concluded that oncolytic viruses have been shown to have low toxicity and high tolerability in preclinical toxicology studies.