Abstract: Because the heat stress is one of the most stressful factors on the biological systems, it was important to study its effect on the development of neurons in different Central Nervous System (CNS) regions of albino rat newborns. Development of neurons in cerebral cortex, cerebellar cortex and cervical and lumbar regions of the spinal cord was followed by using Golgi-copsch stain between days 7 and 21 after birth. The present study does not only illustrate the aspects of development processes of normal neurons in different regions of CNS, but also records the effects of heat stress (40±1°C) on them. The present study revealed that the development of the CNS is extremely sensitive to heat stress which led, in turn, to some harmful effects on the neurons development and caused delay of the dendritic arborization in all investigated CNS regions of the rat newborns. Taken together, further studies are required to determine if the beneficial effects of heat exposure result in changes of stress complications only or not. Thus, experiments will be required to solve these problems and to comprehend the actual role of heatstroke in neurodegeneration of CNS.