The incidence of nausea and vomiting is a side effect that is often found after surgery. The incidence of nausea and vomiting for patients is very disturbing and can reduce the results of surgery so it is often called the big little problem. The purpose of this study was to determine the effectiveness of Ondansetron injection and its combination in reducing nausea and vomiting in surgery patients at Roemani Muhammadiyah Semarang Hospital. This research is a non-experimental study with descriptive methods and retrospective data collection. The data was taken based on medical records of patients who underwent surgery with general anesthesia for the period January- December 2020. Qualitative data analysis included age, sex and body weight and qualitative data in the form of percentages presented in table form. The results were analyzed using the chi square goodness of fit test with a p- value