Objective To observe the effect of different doses of sufentanil analgesia on postoperative nausea and vomiting after microvascular decompression for hemifacial spasm. Methods A total of 183 female patients with hemifacial spasms who underwent microvascular decompression were retrospectively enrolled. Based on the same anesthesia method, according to the use of different doses of sufentanil in postoperative analgesic pump, they were divided into three groups: a sufentanil 2 μg/kg group (group A, n=60), a sufentanil 1 μg/kg group (group B, n=60) and a non-analgesic pump group (group C, n=63). The primary outcomes were the incidence of nausea and vomiting 2, 8 h and 24 h after operation in the three groups. The secondary outcomes were the operation time, the anesthesia time, and the Visual Analog Scale (VAS) score 2, 8 h and 24 h after operation. Results The incidence of nausea and vomiting in group A was higher than that in group B 2, 8 h, and 24 h after operation (2 h χ2=5.67, P=0.017; 8 h χ2=8.57, P=0.003; 24 h χ2=6.72, P=0.010). The incidence of nausea and vomiting in group A was higher than that in group C 2, 8 h and 24 h after operation (2 h χ2=4.47, P=0.034; 8 h χ2=4.55, P=0.033; 24 h χ2=5.01, P=0.025). There was no significant difference in the incidence of nausea and vomiting between group B and group C at each time point (2 h χ2=0.09, P=0.764; 8 h χ2=0.72, P=0.395; 24 h χ2=0.16, P=0.691). Then, 2 h after operation, there was no significant difference in the painless grade of VAS scores among the three groups (P>0.01); the grade of mild to severe pain in group C was higher than that in group A (Z=7.12, P<0.001) and group B (Z=6.06, P<0.001); and there was no significant difference be tween group A and group B (Z=1.73, P=0.085). Furthermore, 8 h after operation, there was no significant difference in the painless grade of VAS scores between group C and group B (P>0.01), and the grade of mild to severe pain in group C was higher than that in group B (Z=5.50, P<0.001); the grade of pain in group C was higher than that in group A (Z=6.45, P<0.001); and there was no significant difference between group A and group B (Z=1.69, P=0.091). Then, 24 h after operation, the VAS score in group C was higher than that in group A (Z=5.62, P<0.001) and group B (Z=5.30, P<0.001); and there was no significant difference between group A and group B (Z=0.06, P=0.948). There was no significant difference in operation time and anesthesia time among the three groups (P>0.05). Conclusions After microvascular decompression for hemifacial spasms, the application of 1 μg/kg sufentanil postoperative analgesia can effectively reduce the postoperative VAS score without increasing the incidence of postoperative nausea and vomiting.