Maintaining periurban agriculture and prime periurban farmland has become a leitmotiv in land use planning and management around many cities in North America and Western Europe since the 1960s. This article focuses on the changing perspectives associated with these planning and management initiatives as well as changing research approaches. Initially, periurban farmland was often seen by planners as a land reserve for urban development. Subsequently, concern was expressed about maintaining the prime agricultural land resource via farmland protection programmes, especially in North America in the 1960s and 1970s. Early research into periurban agriculture involved statistical analyses of farmland losses and changing agricultural production systems, and farmer interviews to identify pressures and opportunities facing periurban agriculture. Gradually, it became clear that maintaining farmland resources and farm activities required more than just ‘protecting’ them from urbanisation. Two types of initiatives developed: (1) the construction of agricultural development plans to ensure sustainable farm development, e.g. in Quebec since 2008, in France since the mid‐1970s and more recently in Wallonia (Belgium) in 2014; and (2) a change in the research approach to support periurban agricultural sustainability. While still using interviews with farmers and other actors, more important is the emergence of action research to provide support to farmers, their neighbours, elected officials and professionals in developing agricultural development plans, with the aim of achieving a better integration of periurban agriculture into the regional urban system. This paper develops this reasoning using research in Canada, France, and principally Belgium to illustrate the argument.