Aim. To study incidence and structure of comorbidity in multiple myeloma (MM) patients depending on their age; to determine its effect on overall survival, efficacy, and safety of the first-line therapy in real clinical practice. Materials & Methods. Overall, 369 patients with newly diagnosed MM were enrolled in the trial from January 2012 to December 2017. Among them there were 134 men and 235 women hospitalized at the Unit of Hematology in the Novosibirsk Municipal Clinical Hospital No. 2. Median age of patients was 67 years (range 32-82 years). Results. The analyzed patients were divided into three age groups: the first group of young/middle age (32-59 years) (n = 105), the second group of elderly patients (6074 years) (n = 186), and the third group of old age (> 75 years) (n = 78). In each patient prior to chemotherapy the comorbidity spectrum was identified and CIRS-G, CCI, and MCI comorbidity scores were calculated. Patients with newly diagnosed MM in real clinical practice prove to have high and increasing with age comorbidity incidence (91 % in patients of young/middle age, 97,7 % and 100 % in patients of elderly and old age, respectively). Comorbidity significantly reduces overall survival (OS) of MM patients. Important OS predictors are rhythm and conduction disorder (odds ratio, OR, 2.762; p < 0.002), chronic pancreatitis (OR 1.864; p < 0.001), exogenous constitutive obesity (OR 1.948; p < 0.002), chronic obstructive pulmonary disease (OR 2.105; p < 0.021), chronic kidney disease, stage С4-С5 (OR 2.255; p < 0.003), and chronic heart failure, functional class II (OR 1.915; p < 0.002). Highest importance in predicting OS, efficacy, and tolerance to chemotherapy in MM patients is attached to MCI score (OR 3.771; p < 0.001). MM patients with high risk by MCI are characterized by lower rate and depth of response to the first-line therapy, shorter time before the first relapse, higher incidence of non-hematologic toxicity of grade > 3, and therapy withdrawal or drug dose reduction.