This article provides a systematic analysis of the challenges of managing agricultural indigenous knowledge (IK), and accessing external knowledge in the rural areas of sub-Saharan Africa, with a specific focus on Tanzania. Semi-structured interviews were used to collect primary data from 181 small-scale farmers in the six districts of Tanzania. The findings indicated that farmers faced various challenges in managing their IK, and accessing external knowledge, which ranged from personal and social barriers, to factors in the external environment such as infrastructure, policy, Intellectual Property Rights (IPR), and weak linkages between research, extension services and farmers. Farmers also faced challenges when using information and communication technologies (ICTs) to manage their knowledge, such as personal, socio-cultural, infrastructural, technical, and economic factors. It is thus important for the government to improve access to extension services, review the IPR system, enhance rural electrification, telecommunications and roads infrastructure. Further, the knowledge providers (i.e. agricultural extension officers, researchers, educators, libraries, non governmental organisations, civil society, and other agricultural actors) should nurture a knowledge sharing culture. Farmers need to be assisted and trained to document their knowledge, map communities' IK bearers and innovators, use multiple formats (print and ICTs) with traditional communication channels (for instance, folklore and apprenticeships) specific to a local context to disseminate knowledge. Participatory approaches should be employed in knowledge production and dissemination in order to include farmers' needs and expressing knowledge in the resulting technologies, practices and new knowledge. In this way linkages between indigenous and external knowledge would be enhanced for improved farming activities in the local communities.