The estimated three million United States migrant and seasonal farmworkers and their families suffer from a variety of occupational hazards and ailments exacerbated by limited, or nonexistent, health care services. Although existing migrant and seasonal farmworker health data is incomplete, general statements can be made about the health risks faced by this population. The migrant population suffers health problems related to poor sanitation and overcrowded living conditions at rates much higher than the nonmigrant population. Provision, maintenance, and use of field sanitation facilities such as toilets and potable drinking water at the worksite would substantially decrease the incidence of sanitation related health problems among farmworkers. Most migrants seek medical treatment for acute ailments rather than chronic conditions or preventive services. Parasitic infections afflict migrants an average of 20 times more than the general population. The full extent of pesticide poisoning is not known and needs further study. The dangers of agricultural labor on women and on the development of farmworker children are poorly documented. Agriculture is the second most dangerous occupation in the United States, yet farmworkers are rarely offered or able to afford health insurance, and in 20 states are not covered by workers' compensation of any kind. (JHZ)