The approach to the etiology of neuropsychiatric disorders can be made by different ways. Among them, the role of thyroid hormones is considered prominent nowadays. The authors report the case of a five year-old boy with congenital hypothyroidism in association with developmental disorders which were manifested by psychomotor retardation, mainly in speech, hypotonia and bilateral hearing loss. Comments are made on the role of hormonal control for a good clinical response, particularly on attention and psychomotor activity.