Purpose: To review the magnetic resonance imaging (MRI) and clinical features in patients with infantile spasms. Patients and Methods: MRI studies of the brain performed over a 7-year period in 37 children with infantile spasms were reviewed retrospectively for presence/ absence of lesions. Lesions were evaluated or location, laterality, and morphology. The corresponding medical records were reviewed to assess the influence of imaging studies on subsequent patient management. Results: The study group included 18 boys and 19 girls ranging in age from 1 day to 6 years. MRI of the brain showed abnormalities in 29 (78%) of the 37 patients with infantile spasms. The most frequent imaging findings were hydrocephalus (n = 13), abnormal corpus callosum (n = 11), atrophy (n = 7), chronic infarctions (n = 4), and periventricular leukomalacia (n = 4). Tuberous sclerosis was found in 4 patients, one of whom had a giant cell astrocytoma at a S-year followup study. Other abnormalities seen included delayed myelination (n = 4), porencephalic cysts (n = 3), neuronal migrational, anomalies (n = 3), bilateral subdural hematomas with accompanying intracranial bleeds from child abuse (n = 2), and Dandy-Walker malformation (n = 1). Surgical treatment of the hydrocephalus and evacuation of the subdural hematomas did not cure the seizures in the affected patients. All of the other entities were considered nontreatable, so those patients received only symptomatic support. In 19 patients, the MRI findings led to appropriate family counseling. Conclusion: MRT demonstrated lesions of diverse etiology in 78% of patients with infantile spasms. The MRT studies proved useful for identifying potentially treatable brain abnormalities and for identifying families who could benefit from counseling.