With a rapidly growing population, increasing manufacturing activity, and increased interdependence, health issues on the US-Mexican border are demanding greater attention. It is unlikely that any other border in the world separates two nations having such variety in health status, entitlements, and utilization. Binational initiatives in the areas of environmental health and sanitation are clearly needed. Further cooperation between the United States and Mexico in provision of health services is warranted and will probably require enhanced federal funding or subsidies to be successful.