The objective of this study was to identify the factors that have affected the adoption of commercial agroforestry systems (AFS) by smallholders of the municipality of Bragança, state of Pará, Brazil. Tools of Rapid Rural Diagnosis (structured interview and direct observation) and of Participatory Rural Diagnosis (agricultural calendar and ranking) were used.. The majority of smallholders that adopted these systems in Bragança received funding from government banks to purchase seedlings and other inputs; in order of importance, access to financing, utilization and management of agroforestry systems, education of farmers and decision-making are determinant factors for adoption of agroforestry systems implanted in smallholders’ areas of the municipality of Bragança, state of Pará.