The article presents the results of dynamic clinical observation of patients, who receive various immunosuppressive therapies, including assessment of PASI index. The efficacy of the combination therapy, including simultaneous administration of sodium salt of the synthetic dipeptide gamma-D-glutamyl-D-triptophane and narrowband phototherapy sessions. The study involved 53 patients diagnosed with moderate “Psoriasis vulgaris, progressing stage” (L40.0), who were treated at the Clinical Dermatovenerologic Dispensary, Omsk region. Assessment of PASI scores by the end of the third week of treatment showed that the combination therapy is more effective than narrowband phototherapy and monotherapy with sodium salt of the synthetic dipeptide gamma-D-glutamyl-D-triptophane and in 31.25% of cases provided clinical remission by the 21th day of treatment.