Abstract The effect of different concentrations of CTAB (in the range of 0.2 mM −2 mM, i.e., including its critical micelle concentration) on viability of selected human cells (osteoblasts and keratinocytes) was studied by a variety of methods (immunocytochemical and biochemical), testing the cell viability and the metabolism, to get a complex overview. All of the used methods confirmed the cytotoxic effect of CTAB, which could, however, be suppressed by the presence of hyaluronan (molecular weight 806 kDa, in the concentration of 1 g/l) in the case of the lowest CTAB concentration used (0.2 mM) when the fetal bovine serum was also present in the cultivation medium. Thus, it could be concluded that hyaluronan can be used as successful protector of specific cell types against cytotoxic CTAB at low concentrations.