Research performed at the Grodno Regional Clinical Center "Phthisiology" was aimed at studying the dynamics of IFN-gamma and IL-4 in serum of patients with widespread forms of pulmonary tuberculosis, treated by polychemotherapy with the use of cycloferon. Results of the clinical and laboratory evaluation of the effectiveness of the basic course of treatment are presented. A total of 238 patients, including 32 patients with limited forms of the pulmonary tuberculosis and 206 patients had widespread forms of pulmonary tuberculosis, were randomized into the basic group (BG) and comparison group (CG), where 95 CG patients received only polychemotherapy and 111 BG patients received polychemotherapy with the use of cycloferon. Data on the initial levels of cytokines (IFN-gamma and IL-4) in healthy persons and patients with various spread ofa tubercular inflammation in lungs are presented and compared. It is established that, in patients with widespread forms, initially low level of IFN-gamma and high concentration IL-4 (in comparison with the limited forms) shows a severe disbalance between Th1- and Th2-mediated immune response. The administration of cycloferon in the complex therapy of patients with widespread forms leads to an increase in the IFN-gamma concentration at initially low levels (below median level of this cytokine in healthy humans). Activation of the Th1-mediated immune response upon using cycloferon leads to an early elimination of clinical manifestations of the intoxication syndrome, positive roentgenological dynamics, conversion of sputum smear, and successful outcomes of treatment.