Purpose To study the variation in IOP following argon laser photocoagulation in the treatment of diabetic retinopathy. Material and Methods Forty patients with proliferative and nonproliferative diabetic retinopathy requiring laser treatment were included in the study. These also included patients with coexisting glaucoma. All patients underwent argon laser photocoagulation. IOP was taken pre-treatment, post treatment at hourly interval for 2 hours on the day of treatment, on 1st and 2nd post treatment day and then on monthly intervals for three months. The data was analyzed using SPSS software version 16. Conclusion There was a significant rise (p<0.005) in IOP after 1-2 hours which lasted for 2-3 days after Argon laser photocoagulation.