OBJECTIVE To evaluate the feasibility and outcomes of phased strabismus surgery under topical anesthesia, with intraoperative comparison of ocular alignment in supine and seated positions. METHODS This retrospective clinical investigation analyzed the data of patients who underwent phased strabismus surgery with fixed sutures under topical anesthesia. The technique consisted of 2 phases, spaced out with an intraoperative alternate prism cover test (performed in supine and seated positions): (1) surgery on one or two muscles, as defined by a preoperative surgical plan; (2) if judged necessary, a further one-muscle surgery. Surgical success was defined as a residual angle of horizontal and vertical deviation ≤±8Δ and ≤5Δ, respectively, and the presence of single binocular vision in primary position in patients with preoperative diplopia. Follow-up visits were scheduled 1 day, 1 month, and 6 months after surgery. RESULTS The review identified 38 patients (age range: 10-80 years). Surgery was well tolerated by all patients. Twelve (32%) required a second phase. No statistically significant differences were found for intraoperative angles of deviation in supine and seated positions. Surgical success was reached, respectively, in 88% and 87% of cases with horizontal and vertical deviation 6 months after surgery. No patients were reoperated during the follow-up period. CONCLUSIONS Phased strabismus surgery is a feasible technique for various types of strabismus in adults and children. Secondly, intraoperative evaluation of ocular alignment can be performed either with the patient seated or supine, with the same accuracy in terms of surgical success.