To compare the recurrence rate following treatment of recurrent pterygia using one of two techniques-limbal conjunctival autograft transplantation versus low-dose intraoperative mitomycin C (0.2 mg/ml) combined with conjunctival flap closure. Randomized clinical trial. Eighty-one patients with recurrent pterygia treated by limbal conjunctival autograft transplantation (n= 41) or mitomycin C combined with conjunctival flap (n= 40) participated. Limbal conjunctival autograft transplantation or low-dose intraoperative mitomycin C application with conjunctival flap technique was performed on recurrent pterygium cases. Recurrence of pterygium and postoperative complications. During mean follow-up periods of 16+/-1.9 and 15.5+/-1.5 months, six recurrences (14.6%) in the limbal conjunctival autograft transplantation group and five recurrences (12.5%) in the mitomycin C group were observed (P=0.77). The difference between the mean ages of recurrent (26.4+/-8.0 years) and nonrecurrent (35.8+/-11.9 years) cases for all patients was statistically significant (P=0.014). Technically, limbal conjunctival autograft transplantation seemed to be more difficult. The most frequent complication in limbal conjunctival autograft transplantation was graft edema, whereas that in the mitomycin C group was superficial keratitis. Both techniques showed similar recurrence rates in the treatment of recurrent pterygia. Although technically easier to perform, further follow-up is necessary to determine the long-term safety of low-dose intraoperative mitomycin C with conjunctival flap closure. The surgeon's familiarity with either procedure should determine the method of choice.