Purpose: To assess the long-term results of esotropia surgery in children with developmental delay who were operated on with reduced surgical dosages. Methods: This was a retrospective analysis of children with developmental delay who had undergone surgery for esotropia during a 16-year period. The pre- and postoperative angle of deviation was calculated for each subject as the mean of distant and near angles measured by a cover test or the Krimsky measurement. The main outcome measure was surgical success, categorized as esotropia or exotropia of ≤10 Δ . Results: The chart review identified 24 children who met inclusion criteria, with a mean age of 2.8 ± 2.5 years (range, 0.8-10 years). The mean angle of preoperative esotropia was 49.8 Δ ± 13.3 Δ . All patients had bilateral medial rectus muscle recessions, with a mean surgical dosage of 5.1 ± 0.7 mm per muscle, on average 0.75 mm less than the standard amount. The average postoperative follow-up was 5.3 ± 3 years (range, 1-13 years). Surgical success was achieved in 9 of 24 children (37.5%) after one operation. Among the 15 failures, 10 (66.6%) were undercorrected, and 5 (33.3%) developed consecutive exotropia. Of these, 8 (53%) agreed to a second procedure. The overall surgical success rate for all patients after all procedures was 63%. Conclusions: Although the initial success rate is low with reduced surgical amounts in children with developmental delays, and some children become exotropic on long-term follow-up, satisfactory results may be achieved with additional procedures.