To examine the epidemiological spectrum of human listeriosis at a large municipal hospital in Miami, we reviewed the cases of Listeria monocytogenes infection seen at the University of Miami Medical Center over a nine-year period (1986-94). Twenty-four patients (13 adults, 11 neonates) with bacteriologically proven Listeria monocytogenes infections were identified. The annual rate of listeriosis for the entire period 1986-1994 was 0.042 cases/1,000 hospital admissions. The rates of listeriosis during the first half of the study period (0.0628/1,000 admissions) were three times higher than the rates observed during the second half of the study (0.0214/1,000 admissions). Four (57%) of the 7 adult cases of listeriosis seen after 1987 occurred in HIV-seropositive patients. Compared with the hospital population, the annual rates of listeriosis were several fold higher in patients post-renal transplant (4.65 cases/1,000 renal transplant-related admissions) and patients with HIV/AIDS (0.27 cases/1,000 HIV-related admissions). No deaths were recorded. The decline in the annual rate of listeriosis noted in our study parallels national trends recently reported by the Centers for Disease Control and Prevention.