Objectives.To compare the frequency, clinical and radiologic manifestations and source of infection of pulmonary tuberculosis in children treated in our hospital during two decades (1978 through 1987 and 1988 through 1997) and to evaluate the influence of the emergence of HIV infection (since 1985) and the effect of the discontinuation of Calmette-Guérin bacillus (BCG) vaccination (since 1987) on childhood tuberculosis.Methods.We reviewed 324 children diagnosed with pulmonary tuberculosis in our hospital during the 20 years (1978 through 1997). The data from 2 decades, 1978 through 1987 and 1988 through 1997, were compared. BCG vaccination in Spain was discontinued in 1987, and HIV infection emerged significantly as a public health problem.Results.An increase in the number of children with single hilar adenopathy was observed (32.2% in 1978 through 1987vs.43.4%, in 1988 through 1997,P< 0.05) in comparison with those with parenchymal involvement or a mixed pattern (62.4% in 1978 through 1987vs. 45.7% in 1988 to 1997). Frequency in extrapulmonary manifestations in both periods was similar, with a nonsignificant trend toward a lower rate of tuberculous meningitis in the latter decade (10.4 vs.5.6%,P= 0.07). We were able to identify an adult source case for 67.1% of the children (100 of 149) in the first decade vs.58.3% (102 of 175) in the second (P= NS); 10.8% of adult contacts but only 2.3% of children (all of them in the second period) were HIV-positive.Conclusions.Discontinuation of BCG vaccination and emergence of HIV infection have had little influence on childhood tuberculosis in our area.