The etiologies of lateral rectus palsy in 132 infants and children seen over a period of 22 years in a university medical center were retrospectively reviewed and compared with similar reports in the literature. Unlike most reports, which lump children with adults, this study focuses on childhood etiologies of lateral rectus palsy. In contrast to the only two studies in the literature on childhood lateral rectus palsy, which reflect a purely ophthalmologic perspective, this study reflects experiences of pediatric neurology and pediatric neurosurgery, as well as ophthalmology. Most lateral rectus palsies were unilateral, almost equally distributed between right and left sides. Trauma, tumor, and congenital etiologies were the most prevalent. The relative frequency of each of these etiologies varies by service (neurology, neurosurgery, ophthalmology). In 10.6% of patients, etiology could not be determined. The majority of patients had an isolated lateral rectus palsy. Association of lateral rectus palsy with other cranial nerve palsies and/or long tract signs characterized trauma and tumor. The majority of tumors were primary and infratentorial. A small number of patients had benign recurrent lateral rectus palsy.