Open-label observational studies can objectively assess treatment in routine clinical practice, which is important from both the scientific and pharmacoeconomical points of view. In 2013, a multicenter open-label prospective observational EQUILIBRIUM study was initiated to describe the Russian experience with Eligard 45 mg used to treat disseminated prostate cancer (PC) in routine clinical practice. A total of 623 patients who had different stages of PC and had been previously treated for this condition were included in the program. The mean age of the patients was 68.9±8.55 years; their mean level of prostate-specific antigen was equal to 42.2 ng/ml and that of testosterone was 89 ng/dl. At the same time, pretreatment testosterone concentrations were measured in only one third of the patients. When included in the program, the patients had a rather high quality of life as evidenced by the EQ-5D-5L questionnaire: its mean index was 0.84±0.18 scores (complete well-being was taken as 1); the mean visual analogue scale health status scores were 75.15±16.5 mm (0, worst health; 100, best health). During the study, most patients received hormone therapy with Eligard 45 for locally advanced PC and distant metastases were detectable in only 15.89 % of the patients.