Isolated limb weakness (monoparesis) has many possible etiologies. Although often assumed to be of a peripheral cause, it can be of central origin. This article describes a case from the Emergency Department of left lower limb weakness in a walk-in male patient on no medications, who had a 50-pack-year smoking history, type II diabetes, and asymptomatic atrial fibrillation. The patient had no history of previous episodes or trauma. His vitals were normal, and his speech and facial function were intact. The patient had full function of his upper limbs, no sensory deficits, and equal reflexes bilaterally. The singular clinical finding was decreased strength in the left leg compared to the right. Imaging revealed a right frontal intraparenchymal hemorrhage, which remained stable throughout his hospital admission. His muscle weakness was significantly improved upon discharge. In general, strokes can present with a variety of symptoms, which increase the risk of misdiagnosis. Monoparesis can be the singular sign of a stroke, and it is more common in the upper than the lower limbs.