The relationship between sustainability and tourists is complex. There has been little increase in the number of studies published over recent years focusing on the concept of 'pro-sustainable' tourists, or the tourist's willingness to pay (WTP) for sustainability, making it increasingly difficult to identify key explanatory factors that determine tourists' WTP for sustainable destinations. To provide a richer understanding of tourists' heterogeneous preferences for sustainable destinations, this study allows us to determine current tourists' attitude toward sustainability and to identify explanatory variables that influence their WTP to enjoy a more sustainable destination. This study surveyed tourists on the Western Costa del Sol (Spain), a mature sun and sand destination that is currently restructuring and facing several developmental challenges associated with sustainability.