The classic bacteriological investigation represents the gold-standard in the diagnosis of tuberculosis. Its disadvantages (the long time until the culture's results, low specificity and sensitivity) imposed certain other rapid and accurate investigations in this field; on the other hand, these tests are much more expensive and demand high technology and dedicated laboratory staff The review presents these new modalities in the diagnosis of tuberculosis (emphasizing the nucleic acid amplification tests) with actual international recommendations for their use.