To identify and examine factors that affect postoperative binocularity in children diagnosed with acquired nonaccommodative esotropia (ANAET).Retrospective chart review.Thirty-four pediatric patients who received surgery for ANAET by 1 surgeon (I.M.) at the Ivey Eye Institute, University of Western Ontario (London, Ont.).A multivariate logistic regression analysis was performed to evaluate the effect of the following factors on achieving stereopsis postoperatively: age at onset of esotropia (AO), duration of misalignment (DOM), presence of A/V pattern, recent intermittency of esotropia, and presence of dense amblyopia.Forty-one percent of all patients achieved stereoacuity of 100 seconds of arc or better. AO was found to be the only factor significantly associated with postoperative stereopsis (adjusted odds ratio = 1.063, P<0.05). None of the children with AO who were younger than 30 months regained bifoveal fixation regardless of their DOM.Age of onset appears to play a crucial role on postoperative functional outcome in children with ANAET. Delayed surgery in children with an age of onset beyond 30 months did not seem to be detrimental to regaining bifoveal fixation.