Objective: To prospectively examine the influence of weight status on urinary and sexual function in clinically localized prostate cancer patients treated by radical prostatectomy (RP). Methods: The Prostatectomy, Incontinence and Erectile dysfunction study recruited patients at 2 US institutions between 2011 and 2014. At baseline, height and weight were measured, and urinary and sexual function were collected by the modified Expanded Prostate Cancer Index Composite-50. This index was repeated at the 5-week, 6-month, and 12-month postsurgical assessments and compared to baseline using linear generalized estimating equations. Logistic equations were used to evaluate the likelihood of functional recovery at the 6- and 12-month assessments. Result: Presurgery, nonobese patients (68.8% of 407 patients) had similar urinary function as those with obesity (P = .217), but better sexual function (P = .006). One year after surgery, 50.5% and 28.9% patients had recovered to baseline levels for urinary and sexual function, respectively. Recovery was not, however, uniform by obesity. Compared to those with obesity, nonobese patients had better urinary function at the 6- (P < .001) and 12-month postsurgical assessments (P = .011) and were more likely to recover their function by the 6-month assessment (OR = 2.55, 95% CI = 1.36-4.76). For sexual function, nonobese patients had better function at the 6- (P = .028) and 12-month (P = .051) assessments, but a similar likelihood of recovery 1-year postsurgery. Conclusion: Nonobese prostate cancer patients had better and likely earlier recovery in urinary function postsurgery, and better sexual function both pre- and postsurgery. These findings support the potential for tailored presurgical counseling about RP side-effects and prehabilitation to improve these side-effects.