Abstract: Background and Objective: The onset of various diseases and especially disabling diseases such as bronchial asthma is often associated with quantitative and qualitative changes in leukocytes. The research aimed to study the features of leukocytes in bronchial asthma patients. Materials and Methods: The study was based on the count of certain leukocyte cells in the peripheral blood of relatively safe donors (30) and bronchial asthma patients (109), including 15 intermittent asthma, 38 mild persistent, 26 moderate persistent and 30 severe persistent asthmatics. Blood smears were used to count the number of leukocytes in donors using the garaeva camera. Lymphocytes were isolated with the zonal centrifugation method and were cultured under standard conditions. Results: The results showed a significant increase in the neutrophil and eosinophil in asthmatics compared to relatively safe donors and this increase was offset by a decrease in lymphocyte and monocyte. The correlational analysis method showed that there is an inverse relationship of dependence between counted lymphocytes and the degree of the disease severity (r = -0.3, р = 0.04, R2 = 0.0734, n = 49) in vivo. In contrast to in vitro, based on slowed cell growth in the medium culture of patients with severe disease, lymphocytes from mild and moderate asthmatics showed a proliferative activity. Conclusion: According to the obtained results, it can be said that an estimation of certain figurative elements in the peripheral blood of patients with asthma would provide information on the actors involved in the initiation of the immune-inflammatory response in asthmatics.