Studies estimate that compulsive buying affects between one percent (Faber and O'Guinn 1992) to six percent (O'Guinn and Faber 1989; Roberts 1998) of the adult population. Compulsive buyers are not the only people adversely affected by the harmful consequences of their behaviour. Their families often share the severe emotional, financial, and social problems created by unmanageable debt. E-commerce may exacerbate these problems. Despite the phenomenal growth of the Internet and exponential projections for future on-line sales, no known research has examined on-line compulsive buying behaviour. This study proposes a series of testable propositions relating to on-line compulsive buying derived from extant compulsive behaviour research. Theoretical and managerial implications of these propositions also are discussed.