The main bibliographic impact factors of ARCHIVOS DE BRONCONEUMOLOGIA for the past two years are estimated. Citations of ARCHIVOS DE BRONCONEUMOLOGIA in 1996 and 1997 by Medicina Clínica and all citing journals grouped under the heading "Respiratory System" in the Science Citation Index were counted. The year the citation appeared and the year of publication of the article in ARCHIVOS DE BRONCONEUMOLOGIA were recorded. The total number of articles published by ARCHIVOS DE BRONCONEUMOLOGIA between 1994 and 1996 were also counted. Based on these data we calculated our journal's impact factor for each year studied. Relative impact factor was also figured. In 1996 the exposure factor achieved was 1.602, the half-life of articles was 2.00 years, the impact factor was 0.069 and the relative impact factor was 1.371. In 1997 the exposure index was 1.477, the citation half-life was 3.00 years and the impact factor was 0.030. In conclusion, the international impact of ARCHIVOS DE BRONCONEUMOLOGIA is modest, although our relative impact factor is greater than that of some other internal medicine publications or specialized journals listed in Journal Citation Reports.