PURPOSE: We reviewed 281 consecutive patients with sensory esotropia or exotropia to determine the prevalence of dissociated vertical deviation in patients with sensory strabismus. METHODS: We reviewed the charts of all patients who received a diagnosis of sensory heterotropia or dissociated vertical deviation and who were examined at the Pediatric Ophthalmology Service at the Texas Children's Hospital between 1973 and 1992. Statistical analyses of the prevalence of dissociated vertical deviation were determined after evaluating the direction of the accompanying horizontal strabismus and examining the temporal relationship of the unilateral vision loss. RESULTS: Dissociated vertical deviation was diagnosed in 35 patients (12.5%). It occurred more frequently in sensory esotropia (22 patients, 18.3%) than exotropia (13 patients, 8.1%) (P = .009). The age at which unilateral visual loss occurred did not influence the development of dissociated vertical deviation. CONCLUSION: Dissociated vertical deviation in patients with acquired loss of vision does not support the contention that dissociated vertical deviation is a genetically predetermined anomaly of binocular vision.