The aim is to study the indicators of neuroendocrine regulation in patients with chronic lichenoid dermatoses. Materials and methods. Studies of neuroendocrine system indicators were performed in two groups of patients: 1–60 patients with psoriasis, 2–56 patients with lichen planus, the control group consisted of 15 healthy individuals, whose indicators were considered normal. Determination of serotonin, histamine, histaminase, corticotropin, adrenaline in the serum of patients was performed by enzyme-linked immunosorbent assay. Results. There was a reliable increase in mean serum serotonin levels relative to control in both patients with psoriasis (228%) and patients with lichen planus (182%), histamine (85% and 76%, respectively); reliable decrease in serum histaminase level by 35% in patients with psoriasis and by 33% in patients with lichen planus relative to control and significant increase in histamine / histaminase index by 167% and 142%, respectively; reliable increase in serum corticotropin levels relative to control by 179% in patients with psoriasis and by 31% in patients with lichen planus. The level of adrenaline also significantly exceeded the control values by 43% in patients with psoriasis and by 37% in patients with lichen planus. Analysis of the average value of the adrenaline / serotonin ratio showed a decrease in its relative control by 57% in patients with psoriasis and by 52% in patients with lichen planus. Conclusions. Unidirectional changes in biochemical, enzymatic and hormonal constants of ergo- and trophotropic systems in both psoriasis and lichen planus have been reported, with the predominance of histamine biosynthesis over its inactivation and the prevalence of serotonergic system over adrenergic one, which was accompanied by significant increase in serum level of serotonin, histamin, corticotropin and adrenalin relative to control and a decrease in histaminase and the average adrenaline / serotonin ratio.