History and Objectives: Due to dangers of vomiting after surgical operation and due to different reports on the therapeutic treatment, the present study will determine the effect of veinal injection of 2 therapies, Dropyridol and Metoclopramide on prevention of vomiting after surgery.

Materials and Methods: A double blind experimental study was performed on 430 individuals undergoing abdominal surgery. The effect of these 2 therapies compared to their perspective control group in prevention of vomiting was determined. Their relative risk and the effect of Dropyridol and Metoclopramide was determined and Chi-square test was performed.

Results: 50.5% of cases were female and the rest were male. Dropyridol was received by 165 patients and 120 patients received Metoclopramide and 145 patients did not received any therapy. The rate vomiting in the 3 groups were 3, 10 and 29 percent respectively (P<0.0005). The rate of nausea and vomiting without Dropyridol 6.7 times the risk was 17% and the rate of vomiting without Metoclopramide was 3.3 times and risk was 7%.

Conclusion: The usefulness of anti-vomiting drugs especially Dropyridol and can have significant effect on the prevention of nausea and vomiting after surgical operation. It is suggested that intramuscular injection of such therapies should be studied.