For facilitation of the detection of bacteria able to reduce nitrates the presently used method of 24-hour broth culture with KNO3 and the method of growing on slant agar cultures with KNO3 (standard method) were compared, with certain modifications introduced. It was found that shortening of the incubation period from 24 to 6 hours and reduction of the volume of broth with KNO3 from 10 to 0.5 ml made possible obtaining of a greater number of correct results as compared to the standard method. In the 24-hour broth cultures with KNO3 done as yet in case of negative results it is indispensable to confirm them in the test with zinc dust. The placement of Griess reagents on points onto colonies growing on KNO3 agar may lead to false positive results.