In 1996, a field survey was carried out in Kiambu District, Central Province, Kenya, to assess pest and disease incidence in Napier grass (Pennisetum purpureum) and collect data on biotic and abiotic factors that may have a bearing on the development, occurrence and severity of smut disease (Ustilago kamerunensis). Napier grass is the major source of fodder for stall-fed dairy cattle in Kenya. In the early 1990s, smut disease was reported. The survey confirmed that U. kamerunensis was the major pest and disease threat to Napier grass production in the country, having spread to 4 districts and occurring in 27% of farm plots sampled. The existence of disease hot spots suggests that the main means of spread is through transport of infected planting material, and that the severity of the disease in Kenya compared with other countries results from an increase in the cultivation of Napier grass over the past decade. From authors' summary. KEYWORDS: TROPAG | Pennisetum purpureum | fungal diseases | Ustilago | feed grasses | Pennisetum purpureum | KENYA | Central Province.