Both mesenchymal stem cells (MSCs) and dendritic cells (DCs) are engaged in the regulation of the immune response parallel to their numerous functions. The main objective of this study was to compare the effects of mesenchymal stem cells isolated from human adipose tissue or human bone marrow on the expression of specific cell surface markers as well as the secretion of some cytokines by monocyte-derived dendritic cells. The set of methods used includes cell cultures, magnetic beads isolation of cells, flow cytometry, ELISA and proteome profiler kit assays. The results obtained show that MSCs isolated from human adipose tissue are more potent immunomodulators of differentiation of human DCs in comparison to the bone marrow-derived MSCs. In both cases the percentages of CD14+ cells were increased in co-cultures of MSCs and DCs and at the same time down-regulated the expression of CD80, CD86 and CD83 as in all experiments the effect of adipose tissue MSCs was stronger. Similarly, the secretion of IL-10 by dendritic cells was up-regulated in co-cultures of MSCs and dendritic cells and the effect was stronger when adipose tissue-derived MSCs were used. Taken together all results presented reveal the higher potential of the adipose tissue-derived MSCs to inhibit the differentiation and expression of functionally important co-stimulatory molecules on the surface of monocyte-derived dendritic cells than the bone marrow-derived MSCs.