The results of researches on the influence of ul-trasonic cavitational processing on microbiological indicators of production made by various authors contradict each other. Some researchers claim that at short-term influence the quantity of viable micro-organisms increases whereas others prove that at ultrasonic influence bacterium collapse. The re-search is devoted to studying the influence of tech-nological parameters (time, frequency and tem-perature) of ultrasonic cavitational processing on microbiological indicators of the grain of cereals enriched with microcells. Control samples of oats and pearl-barley grain had intensive bacterial con-tamination: in oats - 3.4∙103 CFU/g, pearl-barley - 2.7∙103 CFU/g. Ultrasonic processing reduced the quantity of bacteria in all the tests. The increase in the time of processing in the range of 10-30 minutes increased disinfecting efficiency. The rela-tionship between disinfection efficiency and the time of processing were nonlinear and could be adequately described as logistic function at 25 °C and as exponential model at 40 and 60 °C. The increase in the temperature in the range of 2560 °C and in the frequency of ultrasound in the range of 35-42 kHz resulted in rising disinfection speed. Nonlinear model of multiple regressions of joint in-fluence of temperature and frequency of ultrasound on disinfection speed is presented. The most effec-tive combinations of the time of processing, fre-quency and temperature of ultrasound allowed re-ducing bacterial contamination of cereals more than by 90 %.