AIM: The study was designed to evaluate the long term results of intraoperative mitomycin C in patients with one recurrence of pterygium. METHODS: In 45 white patients with one recurrence of pterygium the 'bare sclera technique' was performed and a sterile sponge soaked in a 0.2 mg/ml (0.02%) mitomycin C solution was placed intraoperatively on the sclera for 3 minutes. The control group underwent surgical excision only. Recurrences were analysed by the chi 2 test and the method of Kaplan-Meier (life table analysis); the difference between survival curves was tested by the log rank test. The chi 2 test with Yates's correction or Fisher's exact test were used to analyse the difference in complications and side effects between the two groups. RESULTS: After a mean postoperative follow up of 34.55 (SD 13.70) months, 6 recurrences (12.5%) were observed in the mitomycin C treated patients and 16 (35.6%) in the control patients (p = 0.027). The 24 and 48 month life table success rates were 89% and 83% in the mitomycin C treated group and 66% and 63% in the control group, respectively (p = 0.022). No severe side effects appeared during follow up. Superficial punctate keratitis appeared in the early postoperative period in only seven mitomycin C treated eyes (15.5%) (p = 0.018). CONCLUSION: This study confirms the efficacy of intraoperative mitomycin C in improving the success rate after recurrent pterygium surgical excision.