Following the decline of investments in government extension services in the 1980s and 1990s, community- based extension approaches have become increasingly important. One such approach is farmer-to-farmer extension (F2FE), which is defined here as the provision of training by farmers to farmers, often through the creation of a structure of farmer-trainers. We use ‘farmer-trainer’ as a generic term, even though we recognise that different names (e.g. lead farmer, farmer-promoter, community knowledge worker) may imply different roles.