The main objective of gathering available world-wide information on tuberculosis is to present an overall picture of how tuberculosis infection, morbidity and mortality, can be reflected today and to suggest the necessity to improve international epidemiological statistical intelligence. The highest levels of tuberculosis infection in the world (i.e. 60-80% in children 14 years old) may be found in eastern Asia, Oceania and in several areas in Africa. Considerable differences still do exist between the highest and lowest prevalence level within each continent. The ratio between the highest and lowest prevalence level of infection is varying from 1 to 2 in the Americas, to 1 to 10 in Europe. While, in general, in developed countries the annual infection rate reached 0.5% (1969-1972), in developing countries, annual infection rates of 2% or more were reported. The decrease of the annual infection rate in developed countries is, in general, 10% each year, whereas in the developing part of the world the fall in the rates has been slower or the level even remained constant for the last ten years. The information concerning tuberculosis morbidity is sometimes incomplete or inconsistent because of the lack of standard criteria for diagnosing and reporting tuberculosis. Although the bacteriological confirmation of tuberculosis cases has an important bearing on the recording system, official reports are particularly deficient in this respect. Estimating the total number of newly registered tuberculosis cases, one may say that more than 3.8 million, and approximately 4 million cases could have occurred 1967 and 1971 respectively. The prevalence of tuberculosis cases can be estimated to be around 6-8 in 1967 and 8 million cases in 1971. The highest incidence rates reported in 1971 were in Asia, Oceania and in some African countries (i.e. 250-523 per 100000 population). In Europe and America, tuberculosis incidence did not exceed a level of 200 per 100000 population. The average tuberculosis incidence rate for 1971 in the world may be estimated to be 111.5 per 100000 population (111.4 in 1967).