Abstract This chapter introduces the most important classic tenets in consumer behaviour with respect to their applicability in the tourism field. The chapter first deals with behavioural determinants of a broader nature, concentrating on reference group influences. Next, concepts concerning the individual are presented with a focus on: (i) tourist self-image; (ii) perception and cognition; (iii) motivation; and (iv) attitude and intention. Finally, an overview of the decision-making process is given, and other important determinants of tourist decision making, including the 'evoked set', are discussed.