Objective To observe the incidence of ciliary detachment and its relationship with intraocular hypotension soon after vitrectomy. Methods A total of 46 eyes of 46 patients who underwent vitrectomy were examined by ultrasound biomicroscope (UBM). The patients were divided into three groups according to different tamponade: gas group (11 eyes), silicone oil group (8 eyes) and balanced saline solution (BSS) group (27 eyes). Basing on the postoperative intraocular pressure (IOP), the patients were divided into two groups: IOPlt; 10 mm Hg (25 eyes) and IOPge;10 mm Hg (21 eyes). UBM was applied to determine the tomographic features of the ciliary body 3 days after the surgery. IOP were monitored by noncontact tonometer daily after the surgery. The eyes with ciliary detachment were then examined once a week till the ciliary detachment reattached. The followup period was from 14 to 35 days. Results After vitrectomy, ciliary detachment was observed in 20 eyes of 46 eyes (43.5%), The incidence of ciliary detachment was 27.3％ in gas group, 25.0％ in silicone oil group, and 55.6％in BSS group. The average IOP in eyes with ciliary detachment ［(6.47plusmn;4.49) mm Hg （1 mm Hg=0.133 kPa）］ was significantly lower than that in the eyes without ciliary detachmen ［(15.61plusmn;7.72) mm Hg］ (t=8.031,Plt;0.001). The incidence of ciliary detachment was higher in eyes with postoperative IOP lt;10 mm Hg (68.0％) than that in the eyes with postoperative IOP ge;10 mm Hg (14.3%) (chi;2＝15.60, Plt;0.001). All eyes with postoperative ciliary detachment got spontaneous reattachment within 30 days after the surgery except that one eye had optic disc edema due to severe intraocular hypotension. Conclusions Early postoperative ciliary detachment is a common complication after vitrectomy. Eyes filled with BSS have the highest incidence of postoperative ciliary detachment. Most of the patients with ciliary detachment may get spontaneous reattahment within 30 days after the surgery.