The immediate and the remote effects of the total one-time uniform irradiation with arsenid-hallium laser (wavelength 0.89 mu, pulse power 450 W, pulsed mode 80-3000 Hz) on the new-born Wistar rats have been examined. The complex of tests illustrated the biotropical effects of used laser regimes. The stimulating or braking of the animal's growth was observed in accodanse with the laser regime.