Prism adaptation and the augmented surgery formula are different tools of surgical augmentation. The purpose of this study was to compare these two methods in the management of acquired concomitant esotropia. This was a prospective study of 40 patients with 20 in each group. In the prism group there were six responders with prism build up. There were 14 non-responders including 10 non-responders with further prism build up and four with no prism build up. The mean esotropia angle was 29 ±6.2PD preop and 37.2 ±9.66PD postop with a mean angle build up of 8.2 ±10.14PD. Mean surgery target angle in augmented surgery was 52.88 ±13.3PD. This was higher than the angle of 39.62 ±8.47PD in the prism group. At three-month follow-up, motor success rates were significantly higher in the prism group than the augmented surgery group (90% success overall vs. 55%), although the sensory success rate was not significantly better. In the prism responder versus non-responder patients, sensory success rate was significant. However, when glasses were adapted for the accommodative element, there was no significant difference in groups for success rate. The authors conclude, for non-accommodative esotropia, all patients with prism adaptation, whether responders or not, should have surgery based on the prism-adapted angle.