The ability of the following bacteria: Escherichia coli, Kliebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Pseudomonas sp. to uptake cadmium from water solution was investigated. Based on the parameters of Freundlich and Langmuir equations it was found that the kind of equation describing cadmium uptake by bacteria cells depended on the range of initial cadmium concentration in solution. Cadmium uptake by the investigated strains of bacteria from solution with low initial concentration of cadmium proceeded according to the Freundlich model. Increasing of the initial cadmium concentration above 30 mg Cd2+? dm-3 resulted in a change of the cadmium uptake mechanism and sorption was according to the Langmuir model. The best biosorbents were Pseudomonas sp. and Proteus vulgaris which showed high sorption ability in a wide range of initial concentrations (1-200 mg Cd2+ ? dm-3). In the range of low initial cadmium concentration (1-30 mg Cd2+? dm-3), the most effective biosorbent was Kliebsiella pneumoniae.