Tuberculosis is not always easy to diagnose. All the methods applied in diagnosis of this illness have certain limitations. In this study the value of Rapid Test TB in diagnosis of tuberculosis was evaluated. The aim of the test is to detect antibody against mycobacterial antigen 38 kDa. Material consisted of 100 persons divided into 4 groups: BK(+) tuberculosis patients, BK (0) tuberculosis patients--culture (+), lung cancer patients and patients with sarcoidosis. Positive results were obtained in 100% of culture positive patients and in 10% of patients culture (+), in 20% of lung cancer patients and in 40% of patients with sarcoidosis. Specifity of the test was 55%. The results indicate that Immunozyme Mycobacterium test is valuable tool in tuberculosis diagnosis especially in case when a technical equipment is wanting.