The incidence of H. influenzae meningitis in children under five years of age was monitored during the years 1983-87 by a retrospective study of records from all hospitals serving a metropolitan county in Kansas. The mean annual incidence rate for the five years studied was 26.0 per 100,000. This compares with a mean of 56.0 per 100,000 measured in the same county during 1979-82.