As business becomes more global, understanding consumers' ethical values across cultures has become an important tool for international business, which can be used to formulate strategies to target foreign markets and reduce unethical consumer activity. Therefore, this study focuses on Aberrant Consumer Behaviour (ACB). This behaviour being defined as "behaviour in exchange settings which violates the generally accepted norms of conduct in such situations and which is therefore held in disrepute by marketers and by most consumers" (Fullerton and Punj, 1993:570). Although many studies have attempted to develop a model of ACB, all of these studies are considered as initial stages in a longer process of theoretical development. The current study attempts to follow these stages through developing an ACB model for the Libyan consumer using Ajzen's (1991) theory of planned behaviour (TPB) as an initial analytical framework. In the current study, ACB is examined through three scenarios: shoplifting, stealing from hotel rooms and software piracy. Adopting a mixed methods approach, both qualitative and quantitative data collection techniques and analysis procedures were used in two phases. The two phases of fieldwork were undertaken in Benghazi/Libya. The first qualitative phase investigated the different forms of ACB and explored the impacting and motivating factors from the Libyan marketers' view. The second quantitative phase, a consumer survey, examined interrelations between influences and motivation factors on ACB and ranked them based on their degree of significant effect. In addition to factors which were reported in previous studies and confirmed in this study, the study revealed some rather neglected variables such as consumers being accompanied and dimensions of justice. Comparing the two perspectives of consumers and marketers leads to a wider understanding of ACB in Libya and, therefore, a more fully refined model of ACB for Libyan consumers integrating both perspectives. This model suggests that ACB in Libya is dependent on five groups of variables: the ACB scenario/form , variables related to the consumer, variables related to social and cultural factors, variables related to the organisation and consumer's perceptions. The impact of social variables and religion in Libya goes beyond influencing the consumer intention to adopt ACB. These variables impose some limitations on both marketers' reactions towards ACB offenders and the control and prevention practices they employ to deter it. Instead, they apply alternative practices to those of the West which they find more socially and culturally acceptable.