The Matphyto program was launched as part of the development of job-exposure matrices (Matgéné program) within the Occupational Health Department of the French Institute for Public Health Surveillance to improve understanding and monitoring of occupational risks in the agricultural sector. To accurately identify the numerous pesticides and the significant changes in their use over time, the Matphyto program develops crop-exposure matrices for plant protection products, broken down by chemical families and specific active ingredients. Each matrix lists, for the various crops concerned, all pesticides likely to have been used, accompanied by three exposure indices: a probability of use by a professional at a given time, a frequency of application on a given plot, and an intensity corresponding to the average dose used. The application of these matrices will make it possible to describe the prevalence of exposures, assist in identifying past occupational exposures that may be useful for medical and social care, and aid in the individualized assessment of exposures during epidemiological studies. This document presents the methodology used to establish these crop-exposure matrices, as well as their characteristics and methods of application. (R.A.)