Background: Studies have found associations between cancer therapies and auditory complications, but data are limited on long-term outcomes and risks associated with multiple exposures. Procedure: The Childhood Cancer Survivor Study is a retrospective cohort investigating health outcomes of long-term survivors (5+ years) diagnosed and treated between 1970 and 1986 compared to a randomly selected sibling cohort. Questionnaires were completed by 14,358 survivors of childhood cancer and 4,023 sibling controls. Analysis determined the first occurrence of four auditory conditions in two time periods: diagnosis to 5 years post-diagnosis, and ≥5 years post-diagnosis. Multivariable analyses determined the relative risks (RR) and 95% confidence interval (CI) of auditory conditions by treatment exposure. Results: Five or more years from cancer diagnosis, survivors were at increased risk of problems hearing sounds (RR=2.3; 95% CI: 1.8-2.8), tinnitus (RR=1.7; 95% CI: 1.4-2.1), hearing loss requiring an aid (RR=4.4; 95% CI: 2.8-6.9), and hearing loss in 1 or both ears not corrected by a hearing aid (RR=5.2; 95% CI: 2.8-9.5), when compared to siblings. Temporal lobe and posterior fossa radiation was associated with these outcomes in a dose-dependent fashion. Exposure to platinum compounds was associated with an increased risk of problems hearing sounds (RR=2.1; 95% CI: 1.3-3.2), tinnitus (RR=2.8; 95% CI: 1.9-4.2), and hearing loss requiring an aid (RR=4.1; 95% CI: 2.5-6.7). Conclusions: Childhood cancer survivors are at risk of developing auditory complications. Radiation and platinum compounds are determinants of this risk. Follow-up is needed to evaluate the impact of auditory conditions on quality of life. © 2011 Wiley-Liss, Inc.