BACKGROUND Multiple myeloma (MM) is an incurable disease and autologous hematopoetic stem celltransplantation (HSCT) is the most effective treatment modality. It’s effectivity is evenhigher, when we treat patients with two consecutive autologous HSCT. We present ourexperiences with tandem autologous HSCT in patients with MM. METHODS During the period from 1. 1. 2003 untill 1. 11. 2007 we treated 62 MM patients. After induction therapy and stem cell collection we performed tandem autologous HSCT withinsix-month period. Treatment results were followed with biochemical parameters, monoclonal globulin peak and free light chains in serum. RESULTS Complete remission after induction was achieved in 1/62 (1,6 %) patients, after first HSCTin 6/62 (9.6 %) and after second HSCT in 24/62 (39 %) patients. Putting together CR andPR (partial remission) at three treatment steps, this was achieved in 32/62 (51 %), 51/62(82 %) and 55/62 (89 %) patients. 1/62 (1.6 %) patients died during the treatment. Meantime until relaps was 31,4 months (24.7–38.2 months; 95 % confidence interval) and forsurvival 50,2 months (44.0–56.4 months; 95 % confidence interval). Median relaps timewas 23 months (5.6–40.4 months; 95 % confidence interval), and median time for survival was not reached yet. CONCLUSIONS Treatment of MM patients with tandem autologous HSCT is highly effective treatment modality and our center’s experiences/results are comparable with other transplant centersworldwide. But in Slovenija, we must strictly perform all HSCT related investigations aswell as improve reporting all treatment related data to transplant center