We investigated the long-term outcomes of unilateral medial rectus (UMR) recession surgery in partially accommodative esotropia (PAET). Children aged ≤ 10 years with PAET who had residual esotropia of ≤ 25 prism diopters (PD) after full hypermetropic correction and underwent UMR recession were included. Medical records of patients who were followed up for at least 1 year postoperatively were retrospectively reviewed. Successful outcome was defined as phoria of ≤ 5 PD. Total of 28 patients were included. The mean preoperative esodeviation at distance fixation was 15.5 ± 3.7 PD (range, 10-25 PD). The mean dose of UMR recession was 5.6 ± 0.7 mm (range, 4.0-7.0 mm). The average postoperative follow-up time was 4.4 ± 3.1 years. At the last examination, esodeviation significantly decreased to 6.2 ± 13.8 PD and the surgical success rate was 53.6%. In the success group, the age at surgery was older (P = 0.005), the duration of wearing prism glasses was longer (P = 0.030), and the amount of UMR recession was greater (P <
0.001) than in the failure group. Only half of the patients with small to moderate angle PAET achieved successful long-term outcomes through UMR recession. Having sufficient time to wear prism glasses before surgery to achieve good binocularity and receiving a sufficient amount of surgical correction may improve surgical success.