Antibodies against M. tuberculosis antigenic glycolipids were determined by enzyme-linked immunosorbent assay (ELISA) in 80 sera from patients suspected of pulmonary tuberculosis, with suggestive clinical signs and radiological abnormalities, but smears negative. The test was also performed on 68 control sera from patients with bacteriologically confirmed pulmonary tuberculosis, in different stages of disease. We obtained the test sensitivity of 89.5% for the confirmed tuberculosis patient sera. Low levels of specific antibodies and the sensitivity of 75% were found when using ELISA in smears negative patients at the onset of clinical tuberculosis. The experimental results showed that ELISA could be used as a supporting test in early diagnosis of pulmonary tuberculosis.