Psoriasis is the most common chronic, genetically determined autoimmune polyetiologic inflammatory disease with impaired epidermal proliferation, provoked by exogenous and endogenous factors and manifested by erythematous scaly elements, papules and plaques. Despite the widespread prevalence of psoriasis and a large number of studies on this problem, there is still no single view of the pathogenesis of this dermatosis. For an objective understanding of the pathogenesis of psoriasis, it is necessary to consider the insufficiently studied comorbidity of this pathology. Recently, an undeniable link between psoriasis and obesity has been proven. Taking into account the current data on the role of systemic inflammation underlying the development of both psoriasis and obesity, the study of molecular mechanisms of its development, and taking into account the role of proinflammatory nuclear transcription factors, thiazolidinediones are the pathogenetically determined drug of choice for the treatment of these diseases. In this study, we determined the efficacy of using 45 mg of pioglitazone once daily for six months in the complex treatment of patients with moderate vulgar psoriasis with concomitant alimentary obesity of I-II degree by clinical and immunological studies of systemic inflammation. Analyzing the study results, it was found that long-term use of 45 mg of pioglitazone was effective, led to a decrease in systemic inflammation, and contributed to a milder course of psoriasis in case of recurrent relapse of the disease.