Tuberculosis remains a major public health problem in industrialized countries, especially since 1985, when an increase of tuberculosis epidemiological rates, associated with ageing, transplantations, intravenous drug use, HIV infection, homelessness and a decline in adequate treatment and prevention programs was reported. The increase of immigrants from countries with high prevalence of tuberculosis has also contributed to this phenomenon. In this study epidemiological and clinical features of tuberculosis among immigrant and native patients in Northern Greece during the period 1988-97 are compared, when a migration wave foremost derived from the countries of ex-USSR to Greece was observed. For this purpose a retrospective-prospective study was developed using the data of a Pulmonary Clinic of a Regional Hospital in Thessaloniki, during the above mentioned period. A group of 79 immigrants were compared with 641 native patients. An increasing ratio of immigrants to natives was observed during the calendar time, especially since 1991. The age pattern of immigrant patients had an increase of cases in ages 20-40 years, in contrast with native patients, who mainly belong to the >50 years age group. Statistical significant differences, with greater values for the immigrant group, were observed in terms of positivity of direct smears and cultures. Individual and family history of tuberculosis were more prevalent in the immigrants, compared to natives. No differences were observed between the two subgroups of patients, in terms of family status, educational level, smoking habit and alcohol use. Among the native group patients, COPD, hypertension and diabetes mellitus, due to the age pattern of this group, were more frequent in contrast to the immigrant group patients, who were younger. Pneumon 2000, 13 (1): 73-83