: ObjectiveTo compare the incidence of diplopia after topical or regional injection anesthesia in cataract surgery.: Study designRetrospective, noncomparative interventional case series.: Participants and methodsThree thousand five hundred forty-two consecutive cataract surgeries, performed from March 1998 to December 2001, were studied.: Main outcome measuresIncidence and mechanisms of diplopia.: ResultsTwo thousand one hundred twenty-two patients were operated under regional and 1420 under topical anesthesia. Twenty-four cases of diplopia were observed, 21 (87.5%) in the regional group and 3 (12.5%) after topical anesthesia (P = 0.005). Eleven cases (45.8%) were secondary to motility problems, all in the regional anesthesia group (P = 0.006). Eight cases (33.3%) were secondary to refractive errors or intraocular lens luxation, 5 after regional and 3 after topical anesthesia (P = 0.88). Five cases (20.8%) were secondary to fusion loss, all in the regional anesthesia group (P = 0.06).: ConclusionsIn our study, topical anesthesia was associated with a lower incidence of diplopia relative to regional injection anesthesia. No cases of diplopia secondary to fusion loss or muscle damage were found after topical anesthesia surgery. [Copyright &y& Elsevier]