Intracranial lipomas are extremely rare fat-containing lesions that occur due to the abnormal differentiation of embryonic meninges. Interhemispheric lipomas that are closely related to the corpus callosum are also referred to as pericallosal lipomas and are the most common subtype. Pericallosal lipomas are associated with varying degrees of dysgenesis of the corpus callosum and therefore have a broad clinical presentation. Herein, we describe a case of a 15-year-old man who presented with a history of developmental delay and psychiatric symptoms and was incidentally found to have a pericallosal lipoma on magnetic resonance imaging, prompting clinical correlation.