The functional side-effects of both radical prostatectomy and radiotherapy for prostate cancer are well known. The aim of this study was to evaluate if there was a significant worsening in recovery of urinary continence in those undergoing radical prostatectomy followed by adjuvant radiotherapy versus radical prostatectomy alone. This study included 361 patients either with pT2 disease with positive surgical margins, or pT3a/pT3b node-negative disease. Of these, 153 went on to have adjuvant radiotherapy. Patients were followed up for a mean of 30 months, with 70.4% of patients recovering complete urinary continence (defined as no protective pad use). When the two subgroups were analysed, a significant decrease in urinary continence was noted in the group who received adjuvant radiotherapy, with continence rates at one and three years of 51% and 59%, versus 81% and 87% in the group undergoing radical prostatectomy alone. Univariate analysis found older age, non-nerve sparing disease, non-organ confined disease and adjuvant radiotherapy were associated with lower urinary continence. Multivariate analysis confirmed adjuvant radiotherapy to be an independent predictor of lower urinary continence rates. This paper helps to highlight the need for thorough counselling and careful planning when advising patients on adjuvant therapy. This paper does not include the survival benefit for those undergoing adjuvant radiotherapy in this cohort, however any survival benefit would need to be evaluated in view of altered quality of life associated with urinary incontinence.