In a group of 85 patients with multiple myeloma (MM) incl. 50 patients examined at the time when the diagnosis was established the relationship of the values of the propidium-iodide index (PI index) of myeloma plasmocytes of the patients were examined by flow cytometry using the double staining method, and selected laboratory parameters of the disease were analyzed. It was revealed that the values of the PI index examined with the aid of different "identification" monoclonal antibodies did not differ significantly. The median and average value of the PI index was in the whole group for PI/CD38 2.3 and 2.3%, for PI "UHKT" 1.8 and 1.8% and for PI/B-B4(CD138) 2.2 and 2.4%. In the group of patients examined at the time when the diagnosis of MM was established before chemotherapy the median and average value of the PI/CD38 index was 2.0 and 2.2%, PI/"UHKT" was 1.5 and 1.6%, PI/B-B4 (CD138) 2.6 and 2.5%. In the two analyzed groups no statistically significant correlations of PI/CD38,/"UHKT" and B-B4(CD138) index were found with the number of granulocytes, thrombocytes, immunochemical type and the value of the serum M-component, and levels of S-beta 2 microglobulin, S-urea, S-creatinine, S-calcium, and S-lactic dehydrogenase. A significant positive correlation was found in both groups with the level of S-thymidine kinase, in the whole group of indexes PI/CD38 and PI/B-B4(CD138) with the severity of anaemia, index PI/CD38 correlated with S-albumin and index PI/B-B4(CD138) with the percentage ratio of plasmocytes in bone marrow. It was revealed that examination of the propidium-iodide index is a suitable and prompt method for evaluation of proliferative properties of the myeloma population.