Aim of the study is to evaluate the effects of medical and surgical treatment in divers with paranasal sinus barotrauma (PSB) secondary to chronic rhinosinusitis (CRS). In this retrospective, cross-sectional, descriptive study 40 adult divers with CRS were included. Treatment of divers implied a 5-day course of a systemic steroid and a 6-week course of saline nasal irrigations and topical nasal steroid with mometasone in maximal dosage. If symptoms persisted, functional endoscopic sinus surgery (FESS) was performed. Questionnaires included the Sinonasal Outcome Test-20 German Adapted Version (SNOT-20 GAV), dive-related questions (DRQ) and general questions. Questionnaires were completed retrospectively by recalling the symptoms before and after therapy. Forty of 82 divers completed the questionnaires. Mean follow-up was 42 months (range 13-95 months). There was a statistically significant improvement of the Total score (TS) and of every subscore, except the General Quality of Life score, in the SNOT-20 GAV as well as of the TS in the DRQ. Before treatment, divers who required surgery reported significantly more symptoms than divers who were treated conservatively. Post treatment there were no significant differences between the medical and surgical group. Overall, 35 divers could resume diving after therapy even though PSB still occurred but without complications. Divers with sinus problems can successfully be managed medically and if conservative treatment fails, FESS shows a statistically significant improvement of symptoms and no serious long-term hazards for diving.