The paper deals with removing phenols and cyanides from industrial waste waters, as a result of their biological degradation by means of ultrafiltration membranes with immobilized enzymes coming from bacterial strain Pseudomonas sp. The enzymatic membranes were obtained by ultrafiltration of protein solution trough a membrane made of polyacrylonitrile. Is this way,above 90 percent of the enzymes were adsorbed onto the membrane surface. Such enzymatic membranes were decomposed phenol and potassium cyanide in 70 and 80 percent respectively, during single ultrafiltration at the pressure of 100000 Pa and at two fold reduction of initial volume of waste waters. The retention coefficient of ultrafiltration process amounted to 100 percent for phenol and was above 90 percent for potassium cyanide.