We studied the possibility of using anabolic steroid retabolil injections for complex correction of behavioral and immune parameters in rats with genetic predisposition to catalepsy. Subpopulation composition of lymphoid organ and blood cells was compared in rats with genetic predisposition to catalepsy and Wistar rats after retabolil administration. In rats predisposed to catalepsy, retabolil reduced the total content of thymus cells and increased absolute count of CD8 (+) thymocytes. In Wistar rats, retabolil increased the total cell count and the content of CD4 (+) thymocytes, but reduced the number of CD8 (+) cells. Therefore, changes in the subpopulation composition of thymus cells after retabolil administration were opposite in rats with genetic predisposition to catalepsy and Wistar rats. Retabolil injections reduced the severity of catalepsy response in rats with genetic predisposition. However, the time of freezing in Wistar rats significantly increased under these conditions.