ABSTRACT Background: To evaluate the effect of uncomplicated phacoemulsification on central macular thickness (CMT) and best corrected visual acuity (BCVA) in diabetic patients without diabetic retinopathy (DR) and diabetic patients with mild to moderate non proliferative diabetic retinopathy (NPDR). Materials & methods: A total of 200 diabetic patients (200 eyes) who underwent phacoemulsification were divided into 2 groups as Group A:100 patients withoutDR and Group B:100 patients with mild to moderate NPDR. All patients entered into the study were followed up preoperatively and at 1 month, 6 months and 1 year after phacoemulsification and CMT and BCVA were evaluated at each follow up and tabulated and analyzed by suitable statistical tests. Results: CMT of group A at postoperative 1 month and 6 months was 259.20±20.57µm and 243.48±11.11µm respectively and of group B was 280.03±34.52µm and 254.28±16.46µm respectively. There was significant difference between 2 groups at both postoperative 1 month and 6 months after uncomplicated phacoemulsification. There was no significant difference in the postoperative mean CMT at 1 year between group A (234.03±9.38µm) and group B (240.21±34.00 µm). Mean BCVA Log MAR was 0.15±0.22 in group A as compared to 0.30±0.34 in group B at postoperative 1 month, mean BCVA Log MAR was 0.13±0.12 in group A as compared to 0.20±0.20 in group B at postoperative 6 months, mean BCVA Log MAR was 0.11±0.11 in group A as compared to 0.17±0.15 in group B at postoperative 1 year. ‘p’-value was highly significant in the mean BCVA Log MAR at postoperative at 1 month,6 months and 1 year between the two groups. Conclusion: There was significant increase in mean CMT and mean BCVA Log MAR at postoperative 1 month,6 months and 1 year in both the groups. At postoperative 1 and 6 months there was significant difference in CMT between both groups whereas there was no significant difference in CMT at 1 year between the 2 groups. At postoperative 1 month, 6 months and 1 year, there was significant difference in BCVA Log MAR between both groups.