Sustainable tourism research has attracted wide interest from scholars and practitioners. While several heritage sites are mandated to provide optimum visitor satisfaction with increasing competition in the market, managers of heritage sites face growing challenges in striking a balance between consumption and conservation. This calls for promoting more sustainable behaviours among consumers of heritage. This study proposes a conceptualization of sustainable behaviour for heritage consumers. Using the attitude–behaviour relationship underpinned by the Theory of Reasoned Action, it develops and proposes a conceptual framework that integrates visitors’ heritage experiences, their attachment to heritage sites, and their general and site-specific sustainable heritage behaviour and presents their interrelationships as proposed hypotheses. Theoretical contributions and practical implications for heritage site managers are discussed.