Aim. The evaluation of the activity of selected elements of the immune system in depression. Method. Lymphocyte subsets evaluation (CD3+, CD4+, CD8+, CD 16+, CD 19+, CD4/CD8) was performed in 32 patients with depression (21 women and 11 men in the age from 21 to 66 years) using the flow cytometry method. The cytokine evaluation (sIL-2R, IL-4, IL-6) was performed in 39 patients with depression (23 women and 16 men in the age from 21 to 66 years) using the ELISA method. The evaluation was also performed in 32 healthy controls (16 women and 16 men in the age from 23 to 61). Results. Statistically significant differences were observed in lymphocyte subsets between depressed patients and healthy controls (increase of CD16+, CD4/CD8, decrease of CD3+, CD8+ in depression, decrease of CD3+, CD8+, CD19+ and increase of CD4/CD8 in remission). There were no significant differences between depressed men and women in the above parameters during exacerbation and remission of depression. Statistically significant differences were observed in cytokine concentration between patients during acute episodes of depressions and healthy controls (higher sIL-2R level, lower IL-4 level), but not in remission. Also, there were no significant differences between men and women in the above parameters during exacerbation and remission of the illness. No correlation was found between age and immunological indicators. Conclusion. The results obtained confirm changes of immune system activity in depression, including both activation and supression in the same time. It may suggest an immunological inbalance during depression.