Objective: To assess the safety and efficacy of 0.04% MMC in reducing the rate of pterygium recurrence in primary pterygium surgery. Study Design: Interventional, randomized, prospective, placebo-controlled trials. Place and Duration of Study: Our first study period spanned from February 1996 to December 1998 at Eye Department, Combined Military Hospital - Kharian Cantt and the second from October 2013 to November 2015 at Eye Department, Combined Military Hospital- Lahore Cantt. Methodology: In our study, 0.04% MMC was applied during surgery and comprised of 150 eyes of 116 patients. Results: Recurrence was seen in 33 eyes (44%) in the control group and only 7 eyes (9.3%) in the MMC treated group, showing a drastic improvement in the latter (p<0.05). Recurrence started after 5.63 +1.90 months in the control group and 9.21 +3.67 months in the MMC treated group (p<0.05) showing statistically significant difference between the two groups. Conclusion: MMC 0.04% is a useful adjunct chemotherapy for prevention of pterygium recurrence in our study. MMC not only decreases the recurrence rate, but it also delays the onset of recurrence.