One of the factors limiting the effectiveness of agricultural accident prevention programs has been a lack of knowledge about the nature and true causes of farm accidents;In order to gain further knowledge about the characteristics of farms and people involved in agricultural accidents, several variables from the 1981 Iowa Agricultural Accident and Illness Study were examined. Among these variables were: farm size, farm type, farm work exposure, sex, age, individual exposure to agricultural work and level of formal education. The data were obtained from a random sample, stratified by county, of 2,578 Iowa farms;Farm size was related to accident occurrence, as was farm type. The differences in accident frequencies between farms of different sizes and types can be largely explained by the varying degree of exposure to agricultural hazards. Beef farms, however, had a significantly higher accident frequency rate than other types of farms;Age, sex and exposure to agricultural hazards were related to accident occurrence. Differences in accident frequencies between most age groups can be explained by differences in exposure levels. Persons between ages 5 and 14 had a significantly higher accident frequency rate than other age groups. Females had a significantly lower accident frequency rate than males. This may be because females generally perform less hazardous jobs than males;The level of formal education attained by and completion of tractor and machinery safety programs by tractor and machine operators were found to be unrelated to accident occurrence;The results indicate a need to examine in more detail the effectiveness of certain agricultural safety programs for youth. They also indicate a need for more in-depth study of beef farms to determine the reasons for the high accident frequency rates found to exist;Of the variables examined, exposure to agricultural hazards best accounts for accident involvement. Since it is not practical to reduce the amount of exposure, educational programs and engineering efforts designed to eliminate or reduce hazards associated with farm machinery and livestock should be given a high priority.