The objective of the present study was to investigate the rate of decline in the incidence of tuberculosis (TB) in residents (1985-1994) and in refugees and displaced persons (1992-1994) during prewar and war periods (1985-1994) in the region of Zagreb, Croatia, and to examine a possible change in the trend of decline in the resident population. Data on the incidence of TB were obtained from the Epidemiology Department, Institute for Lung Diseases, Zagreb, Croatia. The sample comprised two groups of subjects: residents (800,000-1,000,000 inhabitants) and all refugees and displaced persons temporarily residing in the Zagreb region (78,000-95,000 persons). Data were analysed by stepwise logistic regression. The most significant predictors of the TB incidence rate were the square of the year and residence status. The rate of TB incidence in nonresidents was significantly higher than in residents. The decline in incidence in residents was significantly slower than in the nonresident group. The results did not indicate a potential change in the natural decline of the incidence of tuberculosis in the resident population during the study periods. The difference between the regression trends of the incidence of tuberculosis in residents and nonresidents was the result of various concomitant factors, including artefacts of the war.