Introduction The outcome of radiotherapy (RT) for prostate cancer (PCA) depends on the delivered dose. While the evidence for dose-escalated RT up to 80 Gy is well established, there have been only few studies examining dose escalation above 80 Gy. We initiated the presented study to assess the safety of dose escalation up to 84 Gy. Patients and methods In our retrospective analysis, we included patients who received dose-escalated RT for PCA at our institution between 2016 and 2021. We evaluated acute genitourinary (GU) and gastrointestinal (GI) toxicity as well as late GU and GI toxicity. Results A total of 86 patients could be evaluated, of whom 24 patients had received 80 Gy and 62 patients had received 84 Gy (35 without pelvis- and 27 with pelvis-radiotherapy). Regarding acute toxicities, no adverse events > grade 2 occurred. 12.5% of patients treated with 80Gy, in 25.7% of patients treated with 84 Gy excluding pelvis, and in 51.9% of patients treated with 84Gy including pelvis suffered from Grade 2 GU acute toxicity (80 Gy versus 84 Gy: p=0.186; with pelvis versus without pelvis: p=0.032). Grade 2 GI toxicity occurred in 12.5% of patients irradiated with 80Gy, in 14.3% of patients treated with 84 Gy excluding pelvis, and in 12.9% of patients treated with 84Gy including pelvis (80 Gy versus 84 Gy: p=0.582; with pelvis versus without pelvis: p=0.510).GU late toxicity of grade ≥ 2 occurred in 4.2% of patients treated with 80 Gy, in 7.1% of patients treated with 84 Gy excluding pelvic RT, and in 18.2% of patients treated with 84 Gy including pelvic RT (logrank-test p=0.237). 8.3% of patients treated with 80 Gy, in 3.6% of patients treated with Gy excluding pelvic RT, and in 0% of patients treated with 84 Gy including pelvic RT suffered from GI late toxicity of grade ≥ 2(logrank-test p=0.358). Conclusion We were able to show that dose-escalated RT in PCA up to 84 Gy is feasible and safe without asubstantial increase in toxicity. Further follow up is needed to assess survival.