The white-rot fungus Bjerkandera sp. BOL-13 was evaluated regarding decolorization of four textile dyes Reactive blue 21, Reactive black 5, Reactive orange 13 and Reactive yellow 206. Experiments were performed in batch and continuous modes. The total dye concentration in all experiments was 100 mg l(-1). The results of the batch experiments showed that the fungus decolorized all dyes but at different rates. There was, however, an increase in the ultraviolet (UV) absorbance when a medium with a low concentration of nitrogen was used. No increase in UV range was observed when the nitrogen concentration was increased. A continuous experiment was performed to study the decolorization of a mixture of three of the dyes Reactive blue 21, Reactive black 5 and Reactive orange 13. Scanning of inlet and outlet samples showed that the absorbance at the peaks in the visible range decreased by 60-66%. The UV absorbance of the outlet increased during the first days of operation after which it decreased again to reach the same level as the inlet. The hydraulic retention time in the reactor was 3 days. The medium containing the higher nitrogen concentration was used in the continuous experiment.