Since the 1970s, the prevalence, morbidity, and mortality of asthma* in the United States and other western countries have increased (1-3). In 1990, related health-care expenditures for asthma were estimated at $6.2 billion, or nearly 1% of all U.S. health-care costs (4). This report updates a previous report (5) on national trends in disease burden for asthma using the latest available data from CDC's National Center for Health Statistics' multiple-cause-of-death file, the National Ambulatory Medical Care Survey (NAMCS), the National Hospital Discharge Survey, and the National Health Interview Survey (NHIS).