The importance of environmental responsibility in tourism is widely accepted. Two main paradigms have emerged: ecotourism – a demand-driven concept limited to nature-based tourism - and sustainable tourism – a supply-sided view characterized by industry regulations. Unfortunately, ecotourism is limited in size, and supply-sided measures implicitly contradict the short-term aim of profit-maximization of the tourism industry. Alternative ways of integrating nature conservation and tourism are needed. This paper reviews tourism-specific pro-environmental approaches and research into pro-environmental behavior in general. A case for a broader demand-driven paradigm is made: the identification of nature-conserving tourists - a target market extending beyond the special interest area of ecotourism and weakening the short-term trade-off of sustainability versus profitability in tourism.