A term female infant had the clinical manifestations and accompanying electrophysiologic studies to fulfill the criteria of Guillain-Barré syndrome. At birth, she presented with generalized hypotonia, paucity of lower limb movements, and diminished muscle stretch reflexes. At 3 weeks of age, motor nerve conduction studies demonstrated evidence of demyelination and axonal involvement. Progressive clinical improvement was observed beginning at the age of 2 weeks with subsequent normalization of clinical examinations and nerve conduction studies. To our knowledge, this patient is the youngest reported with Guillain-Barré syndrome.