Objective: Amyotrophic lateral sclerosis (ALS) is defined as a pure motor disorder without sensory impairment. To investigate whether sensory nerve involvement exists or not even in long-term bedridden state of ALS, we evaluated sensory nerve conduction studies in ALS patients with progressive state. Methods: Sensory nerve conduction studies were measured in median, ulnar and sural nerves. Fifteen patients with ALS (9 men and 6 women; mean age 68.13 years; mean duration of illness 6.26 years) were studied. All patients have been in bedridden state with tracheal ventilation and nutritional support with either a percutaneous endoscopic gastrostomy or nagogastric tube. Three out of 15 patients suffered from diabetis mellitus (DM). We evaluated sensory nerve conduction velocity (SCV) and sensory nerve action potential (SNAP) amplitude, and these parameters were compared with age-matched standard value in controls in reported. Results: Compound muscle action potentials were not evoked in both upper limbs and lower limbs in all patients. SCV of median, ulnar and sural nerve was slowed in 6, 9 and 10 patients, respectively. SNAP of median, ulnar and sural nerve was reduced in 4, 7 and 5 patients, respectively. Reduced both SCV and SNAP of median, ulnar and sural nerve were shown in 2, 5 and 3 patients, respectively. All patient with DM showed mild to moderate neuropathy and seven out of 12 patients without DM revealed slight abnormalities. The findings of sensory nerve conduction studies were normal in 5 patients though 1 of them has been bedridden for more than 10 years. Conclusions: Our result suggested that sensory nerves of some ALS patients are not affected even in long-term bedridden state.