Hypomagnesemia has been associated with multiple neurologic abnormalities, including irritability, seizures, paralysis, and choreiform movements. A patient with short gut syndrome who developed severe hypomagnesemia during an intercurrent diarrheal illness is reported. This patient had a transient neurologic syndrome consisting of hemiparesis, mental status changes, and aphasia which resolved as the magnesium levels returned to normal. Neurologic abnormalities of this child were largely secondary to severe hypomagnesemia and should be included in the list of neurologic abnormalities that can result from this metabolic derangement.