Background <p>Acute idiopathic unilateral hypoglossal nerve palsy is a rare clinical entity that necessitates a thorough diagnostic evaluation to rule out serious underlying etiologies.</p> Case Report <p>A 45-year-old man presented to the emergency department with acute-onset dysarthria and difficulty manipulating food boluses over the preceding six hours. He had noticed his tongue deviating to the right while brushing his teeth. The patient reported no recent history of head or neck trauma, severe headache, neck pain, or flu-like symptoms. There were no associated visual changes, dysphagia, limb weakness, or sensory abnormalities. Neurologic examination revealed an isolated right hypoglossal nerve palsy, evident as rightward tongue deviation on protrusion with mild ipsilateral fasciculations. Strength in the sternocleidomastoid and trapezius muscles was preserved, and the gag reflex was symmetric. All other cranial nerves (I–XI) were intact, and motor, sensory, and cerebellar assessments of the trunk and limbs were normal. Following a systematic diagnostic workup to exclude secondary causes, a diagnosis of idiopathic hypoglossal nerve palsy was established. Treatment with corticosteroids and neurotrophic agents was initiated, leading to progressive improvement and complete functional recovery within five weeks.</p> Conclusion <p>Idiopathic unilateral hypoglossal nerve palsy remains a diagnosis of exclusion. Adopting a structured diagnostic framework enhances clinical evaluation, and early therapeutic intervention may facilitate a favorable recovery.</p>