The optimal lighting conditions for contrast imaging of biological tissues during surgical operations have been studied. In so doing a special experimental setup based on a dynamically controlled led lighting system was used. The operating team selected the optimal illumination of the operating field during work with individual organs and tissues of animals (rats); simultaneously experimental investigations of the spectral characteristics of these biological objects were carried out. Relying on such experimental data, an analysis of luminance and color contrasts, including a comparison with a halogen lamp effect. According to results of studies the need to use special lighting with optimization of its intensity and a wavelength spectrum was confirmed. Such a measure will increase the contrast during surgical operations.