The National Animal Health Monitoring System (NAHMS) was created to address the animal health information needs of producers, consumers, agribusiness, academia, and animal health regulatory officials in the U.S.A. The NAHMS program is designed to collect, analyze and disseminate information about the health and productivity of U.S. agriculture, and has evolved through a series of state pilot projects, each of which used slightly different methodologies in the search for optimal strategies for animal health monitoring. Today, the NAHMS program is in transition from state pilot projects to a national focus. A successful transition requires strategic planning to accommodate the changes which are occurring in U.S. agriculture. In 1990, the NAHMS program will initiate a national survey of swine health, focusing on the period from farrowing to weaning. A total of 1400 herds will be involved. Interviews concerning management practices, facilities and herd health history will be complemented by prospective monitoring of sows and litters between farrowing and weaning. Up to 100 farrowings will be monitored in each herd over a 3-month period. The data generated by the NAHMS program will allow calculation of descriptive statistics on animal health and productivity and analyses of the farm-level characteristics as they relate to health, productivity, and economic efficiency.