Purpose: Patients treated by external beam radiotherapy (EBRT) for localized carcinoma of the prostate (CAP) often suffer from urinary obstruction. While most patients can be treated medically, some require transurethral prostatectomy (TURP) for alleviation of obstruction. The consequences of combing EBRT and TURP are controversial. The objective of this study was to evaluate the success and complication rates of TURP combined with EBRT. Patients and Methods: Between 2001 and 2017, 3501 patients underwent TURP. Sixty-six of them were treated with EBRT for CAP. Surgical complications according to the Clavien-Dindo (CD) scale and the need for secondary interventions were compared to 66 randomly selected patients operated on for benign prostatic hyperplasia (BPH). Results: Patients who underwent TURP for BPH were significantly older compared to the patients with CAP with an average of 76.4 (SD 4.3) vs 71 (SD 8.2) years, p<0.0001. Substantial post-operative complications were rare in both groups with only a single case of CD grade 3 in each group. However, patients with CAP required significantly more secondary surgeries (21% vs 6%, p=0.02) and significantly more additional interventions (37.9% vs 13.6%, p=0.0025). There was no difference in complication rate, in the need for additional interventions or in the oncological outcome when comparing patients operated before or after EBRT. Conclusion:The complication rate of TURP done before or after EBRT is low and comparable to surgery for BPH. However, the rates of secondary surgeries and additional interventions in these patients are high (40%). TURP before or after EBRT provides similar results.