Objective To evaluate the application of adding ondansetron in morphine intravenous analgesia pump for prevention of postoperative nausea and vomiting(PONV)in women. Methods Data of surgical female inpatients who received general anesthesia and postoperative intravenous analgesia with morphine in our center from January 1st,2013 to December 31st,2014 were retrospectively analyzed. Based on whether ondansetron was added,patients were divided into the observation group(n=834) and the control group(n=856). Outcome variables including morphine consumption,visual analogue scale(VAS) score,nausea score,and total times of vomiting within 48 hours after surgery were collected and compared. Results Age(t=0.432,P=0.665),morphine consumption during the first post-operative day(t=0.599,P=0.548) and during the second post-operative day(t=0.236,P=0.813),maximum VAS score of postoperative pain during movement during the first post-operative day [3(2,4) vs. 3(2,5);Z=1.850,P=0.064] and at rest during the second post-operative day [0(0,1) vs. 0(0,1);Z=1.511,P=0.131] were not significantly different between two groups. While the maximum VAS score of postoperative pain at rest during the first post-operative day [0(0,2) vs.0(0,2);Z=2.435,P=0.015] and during movement during the second post-operative day [3(1,3)vs.3(2,4);Z=3.445,P=0.001] were significantly different between two groups. The maximum score of postoperative nausea(χ2=9.810,P=0.020) and cumulative frequency of postoperative vomiting(Z=3.726,P=0.002)in the observation group were significantly lower than those in the control group during the first post-operative day;however,there was no significant difference during the second post-operative day(χ2=5.017,P=0.170;Z=0.000,P=1.000). Logistic regression analysis showed that adding ondansetron in morphine intravenous analgesia pump was an independent influencing factor of reduced postoperative nausea. The probability of nausea during the first post-operative day was 0.781 time(P=0.015)of that in the control group and 0.736 time(P=0.030)during the second post-operative day. Conclusion Adding ondansetron in morphine intravenous analgesia pump may reduce PONV in women.