The aim of the work was established as to study the effect of low-intensity laser therapy (LILT) on the morphology of neutrophils by the method of interference microscopy in correlation with metabolic parameters in the use of modulators which permits to assess the contribution of various structures of neutrophils to the realization of LILT effect. There was in vitro research. The neutrophils of rats served as the object of research. The neutrophils were incubated with adrenalin, cortisol, and β-blockers of adrenoreceptors. The effect of LILT in combination with a preliminary incubation of these substances was studied. Autonomous laser shower MarsiK (R&D company “Petrolaizer,” Saint Petersbourg), a laser therapeutic complex for animals, was used as a laser irradiation source. The wavelength of the irradiation was 830 nm, and the total power was 90 MW. The phasometry of neutrophils was studied by the laser modulation interference microscopy method, the processes of lipid peroxidation were analyzed by the malondialdehyde concentration, and the ATP concentration was defined by spectrophotometry. LILT provoked unidirectional changes in indices in the groups where the neutrophils were incubated with adrenalin, cortisol, and adrenoreceptor blockers. It manifested in the intensification of lipid peroxidation, increase in ATP concentration, and on the other hand, an increase in phase diameter of neutrophils regarding indicators without the impact of LILT. It is shown that the LILT effect intensity may be modified depending on stress realizing hormones (adrenalin and cortisol), β-blocker of adrenoreceptors. It permits us to suppose that the LILT effects may be realized in different ways depending on the state of the cells.