Artificially created social isolation in rodents models a form of chronic stress that causes neurodegenerative changes in the brain and subsequent behavioral changes. The aim of this study was to simulate chronic stress in male rats by social isolation and to determine how chronic stress affects the behavioral and sexual responses of rats. During the simulation of chronic stress, rats were divided into two groups: experimental one, where laboratory animals were kept in separate cells for 10 weeks, and control one, where laboratory animals were kept under normal conditions. Subsequently, a clinical examination of each rat, behavioral tests (“Open Field”, “Forced Swimming of Porsolt”, “Raised Cruciate Maze”) and a study of male sexual behavior were carried out to detect changes in behavioral and sexual responses of the animals. The obtained results of behavioral tests and sexual behavior claim marked changes in behavioral and sexual reactions in the experimental group of animals (high emotional reactivity, reduced orientation and research reactions, high sexual activity and increased aggression against females). Thus, the authors conclude on successful modelling of chronic stress through social isolation. This model can be used at the deeper study and development of methods of neuropsychiatric disorders therapy.