Tuberculosis (TB) is a serious contagious infection that used to fill the mankind with terror for several centuries. The disease is caused by various types of mycobacteria, especially by Mycobacterium tuberculosis. Most often, tuberculosis infects lungs, but it can also attack other parts of the body (the pleura, kidneys, eritoneum, skin, eyes, bones etc). The discovery of anti-tuberculosis medication has radically changed the evolution of tuberculosis, which has become a simple curable infectious disease. At present, there are 8 million cases of symptomatic TB and 3 million deaths reported each year. Thus, TB is the second after AIDS only leading cause of death from an infectious disease in the world. Scientists estimate that about one third of the world’s population is infected with Koch’s bacillus, while approximately in 5-10% of people the latent infection progresses to become an active disease. The research studies carried out in the medical laboratory, the Bacteriologic Control Division of the Pneumology and Phthisiology Hospital, in Botosani (Romania) in 2012 showed that the variation in the incidence of the infection with Mycobacterium tuberculosis in the two source environments (i.e. urban and rural) was due to the major socio-economic differences between the two environments: the poor accessibility to the health care services in the rural areas in comparison to the urban one, the disparities between the rural and urban populations in terms of health education and attitude towards their own health status. The individuals preponderantly affected by the infection belong to the age group of 15-64 years old. As to the susceptibility to anti-tuberculosis drugs, the performed tests have showed an increased sensitivity of the patients to the para-aminosalicylic acid and isoniazid. Despite the fact that important steps have been taken in the world to achieve the set goal, the decrease in the incidence of the disease has been slower and slower in the last years; thus, tuberculosis still remains one of the most redoubtable diseases with multiple medical and social implications of the 21st century.