Objective To determine the efficacy of converse ocular conjunctival flap transposition in the management of pterygium under the microscope.Methods It was a retrospective case series study.One hundred thirteen eyes of 87 patients with pterygium who were treated by surgical excision of pterygium and converse ocular conjunctival flap transposition under the microscope between March 2006 and March 2010 were retrospectively reviewed.The mean age was 66.0±9.8 years and the course of disease was 1-20 years.All patients who underwent surgery were followed up for 1-3 years.Patients were examined 1 week after surgery,including the transposed conjunctival flap,the healing of the donor site and corneal trauma.Recurrence of pterygia or eye movement disorder was noted.Results The most common and persistent complaints were hyperemia,edema,and foreign body sensation at the surgical site,which decreased over a 2-4 day period.At one week,all the conjunctival flaps healed.Seven eyes (6.2％) experienced a recurrence with a small fibrovascular band extending anterior to the corneal limbus 3-14 months after surgery.One hundred and six of 113(93.8％) eyes were free of recurrence.There were no major complications threatening visual acuity in the surgical patients.Conclusion Pterygium excision combined with ocular conjunctival flap appeared to be an effective surgical technique for preventing pterygium recurrence and this technique was a simple and safe alternative for pterygia.