Telephone interviews of random samples of Los Angeles primary care physicians in 1984, 1986, and 1989 obtained information about their AIDS-related practice experiences, and sexual history taking. Data from mid-1989 reveal almost 74 percent have worked up at least one patient for AIDS or HIV infection in the past six months and 39.5 percent are caring for at least one patient with AIDS or AIDS-related complex. Self-reported use of appropriate sexual history questions has improved substantially over this five-year period.