After several years of researches to identify possible neurochemical alterations, at present it is known that autism is characterized and induced by at least three neuroendocrine deficiencies, involving the pineal function and the secretion of its most investigated hormone, melatonin (MLT), brain cannabinoid system, and the neurohypophyseal production of oxytocin (OT). Because of the fundamental role of MLT in sleep regulation, brain cannabinoid system in pleasure perception and control of anxiety, and OT in the affective life, these three neuroendocrine deficiencies might explain at least in part the symptomatology of autism. Therefore, autism-related neurochemical anomalies would involve the same main brain structures responsible for the conscious and the affective life, as well as for pleasure perception. On these bases, a preliminary study was performed to evaluate the influence of a progressive neuroendocrine. Substitutive treatment in autistic children. The study included 30 consecutive patients, by treating the first 12 subjects with the only MLT (100 mg/day in the dark period), the next 12 subjects with MLT plus cannabidiol. (CBD) (10 mg twice/day), and the remaining 6 subjects with MLT plus CBD plus OT (2 mg twice/day). All therapies were orally administered. MLT alone was mainly active in the treatment of sleep disorders. The association with CBD improved the control of anxiety. Finally, the further association with OT was also effective in improving the social and affective relationships. These preliminary results would suggest the possibility to treat the autism spectrum disorders by correcting their main neuroendocrine deficiencies through an exogenous administration.