Objective: to estimate the informative value of clinical signs, history data, and Toll-like receptor 4 and 9 gene polymorphisms (TLR4 (C6898A) and TLR9 (A2848G)) to predict the likelihod of frequent psoriasis recurrences and inadequate therapeutic effectiveness. 425 male and female patients aged 18 to 80 years with progressive psoriasis vulgaris were observed during hospital treatment. The gene polymorphisms were studied by a polymerase chain reaction assay using the diagnostic kits made by the Research-and-Production Firm "Lithech" (Russia). The informative value of the diagnostic signs of the disease and the subjective measures of its probability was estimated using Bayes' theorem in two clinical situations: the prediction of frequent recurrences (more than twice a year) and the lack of significant clinical improvements after a course of routine therapy. Allergic comorbidities; a disease history of more than 3 years; the type of psoriasis predominantly affecting the palms and soles; TLR4 C/A genotype (C6898A); psoriasis guttata; a dermatology quality of life index of less than 10 scores; TLR9 A/A or A/G genotype (A2848G); a skin lesion area of 30% or more; and less than 30 years of age at the disease onset are most informative in predicting frequent recurrences of psoriasis. The most informative signs to predict the risk of reducing the efficiency of conventional therapy are TLR9 G/G genotype (A2848G); TLR4 A/A genotype (С6898А); psoriasis predominantly affecting the palms and soles; allergic comorbidities; a psoriasis area and severity index (PASI) of 20 or more in the first 24 hours; a tendency toward exudation of psoriatic elements; and the presence of psoriasis in relatives. A calculation algorithm has been elaborated to determine the informative value of individual signs of psoriasis, including the data of genotyping, in the group of patients with and without frequent recurrences, with and without considerable improvements and to estimate the total risk of developing the above conditions when the clinical and genetic signs of psoriasis are evaluated in the aggregate. Assessing the prognosis of the disease just when prescribing a treatment option helps take reasoned decisions to expand or change the therapy.