Objective To observe the preventive effect of granisetron on postoperative nausea and vomiting(PONV) after laparoscopic cholecystectomy(LC).Methods A total of 120 ASAⅠ~Ⅱ patients undergoing LC were randomly divided into(3 groups) with 40 patients in each group.After operation,the Group A was given an intravenous injection of 3 mg granisetron,the Group B received 6 mg granisetron,and the Group C received 6 ml normal saline.The incidence of nausea,vomiting,headache,and dizziness of the 3 groups at 0~4 h,4~8 h,8~24 h,and 24~48 h after operation was observed.Results The incidence of PONV in the Group A and B was significantly lower than that in the Group C(P