Limb hypoplasia is a rare congenital disorder. Is usually encountered in patients with segmental spinal dysplasia (SSD), in progressive facial hemiatrophy (Parry-Romberg syndrome) and in other rare conditions. We performed an extensive electrophysiological study in a 18-year-old female with congenital left lower limb hypoplasia, but with no motor and sensory deficit. Electrophysiological investigation comprised motor and sensory nerve conduction velocities, needle EMG, quantitative sensory studies and SEP with standard techniques. The study showed markedly involved large diameter peripheral sensory nerve fibers and intact motor and small diameter peripheral sensory nerve fibers. Extensive electrophysiological investigation in cases of limb hypoplasia has not been previously performed. In this patient congentital hypoplasia of the muscles also involved the peripheral large diameter sensory nerve fibers.