As part of its mandate to conduct epidemiological surveillance of occupational risks, Santé publique France has launched a cohort study of workers in the agricultural sector in partnership with the Agricultural Social Security Scheme, known as Coset-MSA. The objective of this study is to describe the health status of the working population affiliated with the Agricultural Social Security Scheme and how it changes in relation to occupational factors. This report presents an overview of the enrollment phase, describing the preparation steps and the data collection process, particularly the corrective actions implemented and their effect on participation rates. A large sample of 270,000 people randomly selected from the workforce in 2016 was invited to participate by completing an online inclusion questionnaire regarding health and occupational history. By the end of the inclusion wave, 30,320 people had started the registration process to complete the online questionnaire; of these, 29,269 (97%) had completed it, 28,119 (93%) had filled out the first page, and 24,417 (80%) had finished completing their questionnaire. An individual was considered a respondent if they had answered at least one question in the “Lifestyle Habits” section and had provided a response to at least 50% of the unfiltered questions in the health and lifestyle sections. In total, 27,044 people were considered respondents and were included in the initial cohort. In addition to the information collected via the questionnaire, a collection of individual data on healthcare utilization, hospitalizations, and career episodes is being compiled for respondents and a sample of non-respondents through extraction from databases available to health insurance, pension insurance, and the MSA’s information systems. After analyzing non-response by comparing participants and non-participants, an initial epidemiological assessment will be conducted, followed by thematic analyses of exposures and the main health topics addressed in the inclusion questionnaire. Respondents will be re-surveyed via questionnaire in 2021. The descriptive results obtained will be compared with those from other working-age populations.