Subject of investigation: sexual development delay (SDD) in adolescent girls. Objective: an increase in the treatment efficiency of adolescent girls with SDD being, brought up in different microsocial conditions, on the basis of determining clinicopathogenetic peculiarities of the pathology. Methods of investigation: clinical, instrumental, immunofermental, radioisotopic, spectrophotometric and statistical. Scientific novelty of the results obtained: it has been first confirmed that bringing up girls in different microsocial conditions results in different pathogenetic mechanisms of SDD development reflecting on the peculiarities of the pathology clinical manifestations and on effectiveness of nonhormonal methods of treatment. It has been first shown that in adolescent girls with SDD being brought up in complete successful families uterine hypoplasia accompanied by body weight deficiency and SDD is observed more often that in age-matched girls from social risk families. Uterus dimensions correspondingto the age and some disorders in succession of the development of secondary sexual characters, as well as hyperandrogenia dermal manifestations were characteristic of the latter. It has been first proved that the leading role in SDD pathogenesis in the girls from complete successful families belongs to a decrease in the hypophysis gonadotropic activity, causing hypoestrogenia, and in the girls from social risk families this role belong to the absence of PRL stimulating impact on sexual development (when its level is decreased) against the background of increased indolamines (serotonin and melatobin) levels. It has been first established that in patients with SDD from sociopathyc families high stress signs were more characterictic, while in optimal microsocial conditions personal anxiety has been observed. Certain differential methods of treatment for adolescent girls with SDD in compared groups have been first scientifically substantiated. Practical significance of the results obtained: different significanceof the risk factors as regards SDD development in girls from various types of families has been observed. In complete successful families they are: small birth body weight of mature fetus, SDD in prepuberty and disorders in digesteva system; in social risk families they are: complicated course of perinatal peiod, chronic phychiemotional stress, CNS diseases. By refined determination of SDD pathogenetic mechanisms and clear definition of peculiarities in the pathology clinical manifestations in girls being brought up in different microsocial conditions, there heave been proposed pathogenetically grounded differentiated treatment methods (Patents of Ukraine No. 28644А, No. 45623А, No. 68530А). It has been shown that prognostically unfavourable sign as regards the effectiveness of regular stimulating therapy in girls from social risk families is represented by a decreased blood PRL level, in those from complete successful families such sign is represented by pronounced hypoestrogenia. The necessity for timely application of sexual development hormonal stimulation in the girls from unhappy families as early as at second degree SDD stage has been substantiated.The developed treatment methods for adolescent girls with SDD have been introduced into practical work of children’s and adolescents’ gynecologists at the regional children’s clinical hospital No 2 of Dnipropetrovsk, at the municipal hospital No.3 of Mariupol, at the municipal clinical maternity hospitals in Vinnitsa (No. 1) and Chernivtsy (No.1), at the regional children’s clinical hospital of Lugansk, at Kharkiv interregional center for family planning and human reproduction. Theoretical data have been employed in the training process at the department of perinatology and gynecology (with a course in pediatric gynecology) at Kharkiv Medical Academy for postgradual education. The state of practical use: everyday practice of children’s and adolescents’s gynecologists and therapeutist, family doctor. Fields of application: practical health care, children’s gynecology and pediatrics, family medicine.