Background and objective: Postoperative nausea and vomiting (PONV) after ophthalmic surgery under general anaesthesia remains a complex and perturbing complication associated with several factors. Little information is available regarding the risk factors for nausea and vomiting after vitrectomy in adults. In this study, we evaluated the potential risk factors for PONV after vitrectomy in adult patients. Methods: Univariate and multivariate analyses of clinical factors associated with PONV were undertaken in a retrospective case–control series of 247 adult patients undergoing vitrectomy under general anaesthesia. We examined PONV for the first 48 h. Factors examined were age, body mass index (BMI), smoking status, H2-blocker as premedication, type of general anaesthesia (sevoflurane and fentanyl or total intravenous (i.v.) anaesthesia with propofol and fentanyl), duration of surgery, and intraoperative fentanyl dose. Results: Fifty-nine patients (24%) reported one or more episodes of PONV during the study period. Female gender (P < 0.01), lower BMI (P < 0.01) and general anaesthesia with inhalational anaesthetics (P < 0.01) were significantly related to nausea during the first 2 h postoperatively. Female gender (P < 0.01) was significantly related to nausea and vomiting throughout the study period. Other factors, including smoking status, did not alter the risk for nausea and/or vomiting. Conclusions: We conclude that female gender, lower BMI and inhalation anaesthesia are the main risk factors for PONV after vitrectomy in adults. Smoking status did not reduce the incidence of PONV in our patients.