Aim. To compare toxicity and efficacy of high-dose melphalan chemotherapy with subsequent autologous hematopoietic stem cell transplantation (auto-HSCT) in multiple myeloma (MM) patients aged under and over 60 years. Materials & Methods. The retrospective analysis was conducted on the data of 107 MM patients, 78 of them were aged under 60 years (median 54 years), and 29 of them were aged 61 years and older (median 63 years). All patients received auto-HSCT in the period of 2017–2022. Single and tandem auto-HSCT were performed in 92 and 15 patients, respectively. Patients with tandem auto-HSCT (n = 15), lost to follow-up patients (n = 8), and patients who died during early post-transplant period (n = 4) were excluded from survival analysis. Survival rates were calculated based on the date of auto-HSCT. Results. A comparative evaluation of the results in two age groups showed a significant difference in the number of patients treated with ixazomib during the induction period (р = 0.019) and cyclophosphamide 3 g/m2 as part of auto-HSC mobilization (р = 0.014), as well as 200 or 140 mg/m2 melphalan as part of conditioning regimen (р = 0.039 and р = 0.009, respectively). With a follow-up median of 13 months (range 1–57 months), the median progression-free survival in the groups ≤ 60 years vs. > 60 years was 32 and 47 months, respectively (hazard ratio [HR] 0.688; 95% confidence interval [95% CI] 0.270–1.754; p = 0.704). The median overall survival in patients aged under 60 years appeared to be 57 months, it was not reached in patients aged 61 years and older (HR 0.689; 95% CI 0.169–2.803; р = 0.577). Conclusion. The results of the study suggest that all newly diagnosed MM patients aged under 70 years should be regarded as being eligible for auto-HSCT.