This paper explores the environmental knowledge of small-scale rural landholders and comments on the implications of this for environmental policy. The paper draws on conceptualisations of knowledge as ‘know what’, ‘know why’, ‘know how’ and ‘know who’, recognises a distinction between tacit and codified environmental knowledges and highlights the need to consider the politics of knowledge surrounding environmental issues. Both quantitative and qualitative data are reported, and are derived from structured interviews with 30 small-scale landholders who were participants in a nature and landscape conservation initiative – the Landscape Heritage Scheme – within South Devon, England. These data are used to explore the place of environmental concerns within the land management objectives of respondents; the nature and extent of their environmental knowledge; how a range of factors alongside their environmental knowledge shaped the environmental practices of respondents; and the politics of knowledge associated with the Landscape Heritage Scheme. The paper suggests that small-scale landholders should be of interest to environmental policy, prioritising environmental objectives in their land management, being relatively knowledgeable about the environment and highly responsive to environmental advice and financial incentives that support environmental management. A case is made for developing research in this area, given ongoing processes of rural demographic change and the rising importance within this of an increasingly diverse landholding population.