The magnitude of problem with tuberculosis lies in the fact that one third of the world population is infected by Mycobacterium tuberculosis. Even in the 21st century, tuberculosis kills more people than any other infective agent. Definition of case of resistance--the case of resistant tuberculosis is precisely defined by the recommendations of the World Health Organization as primary, initial, acquired multidrug resistant and extensively drug resistant tuberculosis. The development of resistance tuberculosis may result from the administration of mono-therapy or inadequate combinations of anti-tuberculosis drugs. A possible role of doctors in the development of multi drug-resistant tuberculosis is very important. Actually, multi drug-resistant tuberculosis is a direct consequence of mistakes in prescribing chemotherapy, provision of anti-tuberculosis drugs, surveillance of the patient and decision-making regarding further treatment as well as in a wrong way of administration of anti-tuberculosis drugs. The problem of extensively drug-resistant tuberculosis in the world has become very alarming. In South Africa, extensively drug resistant tuberculosis accounts for 24% of all tuberculosis case. It can be concluded that only adequate treatment according to directly supervised short regiment for correctly categorized cases of tuberculosis can stop the escalation of multidrug or extensively drug resistant tuberculosis, which is actually an incurable illness in the 21st century.