Introduction. The study of risk factors, defects of cellular and phagocytic links of the immune system with differing degrees of asthma control allows us to determine the features of chronic inflammation and predict the course of the disease. Aim. To assess risk factors and establish the severity of immunological disorders according to the state of the cellular and phagocytic links of the immune system in partially controlled mild asthma. Materials and methods. The study included 184 patients (aged 25 to 50 years) with diagnosed mild asthma, 125 of them with partially controlled course (main group), 59 patients with controlled asthma (comparison group). Risk factors were identified in all patients. CD3+, CD3+CD4+, CD3+CD8+, CD16+CD56+, CD3+CD19+ were determined by flow cytofluorimetry. The phagocytic link was evaluated based on the phagocytic activity of neutrophils, phagocytic reserve, phagocytic number, phagocytic number reserve, metabolic activity of neutrophils, neutrophil activation index and its reserve. The control group consisted of 17 healthy volunteers who did not have chronic respiratory diseases. Results. In patients with partially controlled asthma, allergic pathology of extrapulmonary localization was 3.8 times more common, foci of chronic infection were 2 times more common, and chronic herpes virus infection was 2.2 times more common. In case of partially controlled asthma, there was an increase in CD3+4+ lymphocytes by 16% (p<0.001), CD3+4+/CD3+8+ index by 1.2 times (p<0.05), a decrease in CD16+56+ by 19.6%, and CD3+8+ cells by 19.5% (p<0.001) as compared to patients with controlled asthma. Disturbance of the functional and potential capabilities of phagocytic cells was characterized by a decrease in the phagocytic number by 26.5%, the HCT test by 1.4 times (p<0.001). Conclusion. Factors hindering the achievement of control in partially controlled mild asthma may be concomitant allergic diseases, chronic herpes virus infection, a characteristic imbalance of cellular and phagocytic immunity.