Registration of the changes in the functional metabolic status of neutrophils under the influence of low-intensity laser radiation (LILR) can be useful for the choice of the exposure parameters in the studies designed to evaluate immunotropic effects. Such investigations, in their turn, are very promising in clinical terms since their results can be used to optimize the laser therapy techniques. The objective of the present study was to evaluate the degranulation potential of neutrophils and the intensity of their NADPH-oxidase reaction in response to the exposure to laser radiation as exemplified by the release of lysosomal granules in vitro. The source of radiation was the LASMIK device operated in the continuous mode at the following parameters: wavelength 635 nm, power density 0.12 mW/cm2, exposure time 10, 30, 90, 120, 150 s in the case of the automatic timer control and 100 s in the case of manual shutdown. It was shown that the maximum lysosomal activity and release of lysosomal granules took place at a 90-10 s exposure and a wavelength of 635 nm with the appearance of a plateau within 120 and 150 s after the onset of irradiation. In the case of a shorter exposure of neutrophil granulocytes to LILR (10 and 30 s) no pronounced effect was observed. It means that low-intensity laser radiation of the red spectrum with a wavelength of 635 nm is a physical stimulus reinforcing exocytosis of lysosomal granules by neutrophils in vitro. The reliable changes of NADPH-oxidase activity of neutrophil granulocytes isolated from donor peripheral blood are recorded at an optimum exposure time of 90-100 s. It is concluded that the laser therapy techniques, at least those designed to regulate neutrophils should be applied with the optimum exposure time of 90-100 s.