In order to estimate minimum AIDS incidence in Spain between 1992 and 1995, annual AIDS incidence up to 1991 has been obtained from the June 1992 update of the National Register. Correction was made for reporting delays in cases diagnosed since July 1989, in order to run a subsequent back calculation on all cases and for each separate mode of transmission. It was assumed that no new HIV infections would appear after 1991. Since 1981 to 1995, more than 38,000 AIDS cases will have been diagnosed. Minimum AIDS incidence as forecast exhibits a rise between 1992 and 1995 for the total number of cases and for all categories of transmission, except for recipients of blood and blood products, and children of mothers at risk. Real incidence will probably prove higher than estimated owing to the effect of new infections which may arise, and to the underreporting of cases.