Objective To evaluate the therapeutic effects of vitrectomy on chronic and refractory Behcet′s diseases. Methods The clinical data of 8 patients (10 eyes) with Behcet′s diseases from 0.5 to 3 years after vitrectomy were retrospectively analyzed. Pre-and post-operative visual acuity, control of inflammation after the surgery, and the recurrence were observed and analyzed. Both of the eyes were involved in all of the patients, including complete Behcet′s diseases in 5 and incomplete in 3. Results Vitreous opacity and liquefaction were found in all of the involved eyes, dark retina and thin retinal vessels were seen in most of the eyes, and vascular obstruction or sheath-like changes in different degrees were detected in some eyes. Improvement of visual acuity was observed in all of the eyes which had undergone the treatment after the operation. There was significant difference between the visual acuity before the surgery and at the 1st and 2nd week and the 1st and 6th month after the surgery. During the follow-up period, recurrence of the inflammation was found in 3 eyes within 1 month and in 6 eyes within 6 months; no recurrence was found in 4 eyes after the operation. No acute recurrence of inflammation was found after operation in the involved eyes. Conclusion Vitrectomy for chronic and refractory Behcet′s diseases may improve the visual acuity of the involved eyes, and the surgery is safe and effective. (Chin J Ocul Fundus Dis, 2005, 21: 357-359)