To compare the surgical outcome of unilateral lateral rectus recession and bilateral lateral rectus recession in moderate-angle exotropia (< or = 30 prism diopters [PD]). The charts of all patients with moderate-angle exotropia (30 PD) who were operated on during the years 1993 to 2005 were retrospectively reviewed. Twenty-nine patients underwent unilateral lateral rectus recession (group 1) and 27 patients underwent bilateral lateral rectus recession (group 2). Exotropia improved an average of 9.4 +/- 7.1 PD in group 1 and 15.5 +/- 10.6 PD in group 2 (P < .05, independent samples Student's t test). The success rate, defined as deviation of 10 PD or less, was achieved in 69% of patients in group 1 and 74% of patients in group 2 (P = .67, chi-square). No postoperative complications occurred in either group. Similar postoperative success rates were achieved with unilateral lateral rectus recession and bilateral lateral rectus recession.