This data paper presents a survey conducted in a participatory manner in the territory of Santarém, in the Brazilian Amazon. The aim is to understand how global changes are affecting family farmers. In the study area, family farming has been confronted over the past 20 years with the rapid expansion of large-scale monocultures, especially soybean. As part of the Odyssea socio-environmental observatory, academic researchers and family farming organizations entered into a partnership to co-produce data that could be strategically useful for these organizations. A process of co-construction of the expectations allowed priorities to be established and the data collection strategy to be defined. Three levels of analysis were chosen in order to allow an integrated understanding of the dynamics of change: the Santarem Plateau territory, the rural community level (living place recognized by the farmers) and the farmers’ households. Twenty-one farmers, called community researchers, organized in 3 teams, applied a questionnaire through the KoboCollect smartphone application to 544 families in the municipalities of Santarém, Mojuí dos Campos and Belterra. Meetings were previously held in the rural communities and questionnaires were applied with representatives of 32 communities. Data was collected between April and June 2019. The community researchers and academic researchers then came together for two collective sessions of data analysis and interpretation in July and October 2019. Data was standardized and cleaned using SPSS software, between September and December 2019. The metadata and databases are available on the CIRAD dataverse.