OBJECTIVE Pterygium are triangular growths of fibrovascular tissue of the bulbar conjunctiva that ultimately cause visual disturbances. Surgical removal is the initial treatment of choice for pterygium, but the recurrence rate after excision alone is 20-40%. The purpose of this paper is to reaffirm the effectiveness of postoperative irradiation with a 90Sr eye applicator. METHODS From 1993 to 1996, 361 patients (393 lesions) were treated with 90Sr postoperative radiation therapy. Forty-five lesions were recurrent cases. All cases had been excised using the "bare sclera" method. Postoperative radiation performed within 48 h after surgery received radiation doses of 30 Gy, the others received doses of 35 Gy, using the 90Sr eye applicator. RESULTS Thirty-four (8.6%) of the 393 lesions recurred. The overall 1-year local control rate was 93.7%. Seventy-one percent of the recurrent cases were noticed within 1.5 years after treatment. The multivariate analysis for total cases demonstrated that sex, age, prior treatment, and duration of pterygium affected the overall local control rate. No complications from this treatment have been observed. CONCLUSIONS It was reconfirmed that postoperative irradiation was effective in preventing local recurrence after surgical removal of pterygium.