The purpose of this study was to evaluate the effect of improved control with part-time occlusion treatment on the final postoperative surgical outcome in patients with intermittent exotropia. Eighty-nine patients were recruited who had unilateral lateral rectus recess / reset procedures for basic type exotropia and with >50% compliance with preoperative part-time occlusion and postoperative follow-up of >1 year. Patients were aged 3.52±2.35 years; 40 males and 49 females; 87.6% had patching of the fixing eye and the remainder with alternate eye occlusion. Mean duration of occlusion was 11.43 months. The mean deviation before occlusion was 27.61±5.40PD for distance and 29.82±5.28PD for near. After occlusion and pre-surgery, it was 26.17±5.09PD for distance and 27.26±5.56PD for near. Forty-nine patients showed an improved control grade. A successful surgical outcome was achieved for 77.6% in the improved control group versus 50% in the no improvement control group. The authors conclude improvement of control grade preoperatively may lead to better surgical success rates.