The Agricultural Health Study (AHS) is a large epidemiologic study of registered pesticide applicators and their spouses in Iowa and North Carolina (Alavanja, Sandler et al., 1996). A goal of this study is to enroll 75,000 of these individuals and follow them for at least the next 10 years to evaluate the role of agricultural exposures in the development of cancer and other diseases. Enrollment began in December 1993. As of October 1996, 73,500 individuals had enrolled with 46,000 coming from Iowa and consisting of 5,400 commercial pesticide applicators, 26,100 private applicators, and 14,500 spouses of private applicators. The objectives of the AHS are to: 1) identify and quantify cancer risks among men and women associated with specific agricultural exposures and practices ~ 2) identify and quantify cancer and other disease risks associated with diet, cooking practices, and chemicals resulting from cooking processes~ 3) evaluate cancer risks among spouses and children of farmers that may arise from indirect exposures to agricultural chemicals ~ 4) study relationships between the development of cancer and agricultural exposures, biomarkers of exposure and disease, and genetic susceptibility factors~ 5) develop an integrated exposure assessment strategy for agricultural exposures that incorporates periodic interviews with environmental and biological monitoring~ and 6) provide an agricultural population for research on health conditions other than cancer. The AHS has three major components: 1) main cohort study, 2) nested case-control studies, and 3) exposure assessment study. The purpose of this report is to provide descriptive information comparing questionnaire responses between commercial and private applicators who have enrolled into the AHS with an emphasis placed on information related to pesticide use.