Objective: To synthesize peer‑reviewed knowledge on the frequency of different types of chemotherapy medication errors. Methods: The data were collected from studies published between January 1, 2000, and March 3, 2018, and are identified through online resources such as Medline/PubMed, PubMed Central, Agency for Healthcare Research, and Quality and the Cochrane Library. The manuscripts published in peer‑reviewed scientific journals in English language were included in the study. Initially, 19,723 articles were retrieved and finally 11 were found to be eligible to include in the review and were assessed for quality. Error percentages were calculated from the ratio of error type (numerator) to sample size (denominator: medication orders or prescriptions).