Urinary and sexual function and bother are important outcomes following radical prostatectomy (RP). Since urinary and sexual function are age-related, post-operative bother may vary by age. This study explores the disease-specific quality-of-life outcomes in young men compared with older men undergoing RP. Using CaPSURE data, we identified men who underwent RP and completed the UCLA Prostate Cancer Index (PCI) before and 1-year post-RP. Men were stratified by age (<55 years, 55–64, ⩾65). Multivariate regression models were created: a linear model for predictors of PCI scores and a logistic model for predictors of severe declines in PCI domains. Younger men scored significantly better than older men in urinary function (P=0.04), urinary bother (P=0.02) and sexual function (P<0.0001) 1-year post-RP. Severe declines in urinary bother (odds ratio (OR)=1.54, 1.01–2.35) and sexual function (OR=3.20, 1.97–5.19) were more common in men ⩾65 years. Men with relationships had less urinary bother (P=0.03) and were less likely to experience severe worsening of urinary bother (OR=0.32, 0.17–0.60) while having a greater risk of severe worsening of sexual bother (OR=2.74, 1.28–5.89). The use of sexual aids was associated with worse sexual bother (P<0.0001) and greater risk of severe worsening of sexual bother (OR=2.29, 1.54–3.30). Baseline PCI scores were independent predictors in all models. One year after RP, younger men (age<55) have similar, or better, urinary and sexual function and bother. Baseline scores are strongly associated with post-RP scores and severity of declines. Current relationships and use of sexual aids have significant roles in post-RP bother.