Recreational misuse of nitrous oxide, a laughing gas, has increased sharply among young adults in recent years. This misuse can lead to multiple complications affecting several organs, including the central and peripheral nervous systems. Spinal cord and peripheral nervous system disorders are among the neurological complications most often due to vitamin B12 deficiency. We report the case of a 20-year-old patient who regularly took nitrous oxide. He presented with subjective sensory signs of paresthesia. Clinical examination revealed a peripheral neurogenic syndrome of all four limbs. Electromyography showed axonal, predominantly motor-sensory polyneuropathy of all 4 limbs, with a length-dependent course. Biological findings showed an increase in plasma methylmalonic acid. Management was essentially based on vitamin B12 supplementation, introduction of Pregabalin and functional rehabilitation. Progression was favorable, with a partial motor recovery after 3 months.