BACKGROUND : Tinnitus can occur during and after treatment for childhood cancer. Studies on the occurrence of, and risk factors for tinnitus during and after childhood cancer treatment are scarce. The aim of this study is to get insight into the frequency and risk factors of tinnitus during and after childhood cancer therapy, based on a review of all previously reported literature. METHODS : Systematic electronic literature searches that combined childhood cancer with different treatments and tinnitus terms were performed in the databases EMBASE, Medline, Cochrane, Web of Science, and Google Scholar. Studies were included based on reporting the frequency of tinnitus during and/or after childhood cancer, with 75% of participants being under the age of 25 at time of diagnosis, diagnosed with any type of childhood malignancy and treated with any type of chemotherapy and/or radiotherapy. A risk of bias assessment per research question was performed. RESULTS : Tinnitus incidence rates were reported up to 15.9 (95% CI 11.8-21.4) during therapy and up to 5.4 (95% CI 4.3-6.9) more than 5 years after diagnosis. The relative risk of developing tinnitus as compared to siblings during and after childhood cancer therapy were reported up to 17.2 (95% CI 11.8-25.0) during therapy and up to 3.7 (95% CI 2.7-5.1) more than 5 years after diagnosis. Independent risk factors for tinnitus development included high dose cranial radiation and platinum based chemotherapy. CONCLUSIONS : The frequency of and risk to develop tinnitus seems to be higher in childhood cancer patients and survivors as compared to the normal population. Regular tinnitus screening before, during and after therapy with standardized questionnaires for early detection seems therefore reasonable in order to identify high-risk patients and eventually develop successful clinical preventive, supportive and management strategies.