Human aging is followed by the weakening of cognitive functions of the brain. The relevance of the study of this process as well as the search for ways of its medical correction increases due to the rise of the middle life span in developed countries. Non-human primates are recognized as the most appropriate biological model for the experimental study of natural cognitive aging mechanisms. The review presents the latest data characterizing age-related behavioral patterns of these animals and the corresponding structural-functional and molecular-cellular correlates. Some effective ways preventing natural senile cognitive decline are highlighted.