Purpose - This chapter seeks to understand the concept of consumer misbehavior, especially in the form of consumer deviance and/or dysfunction. Method/approach - We review the marketing literature on consumer misbehavior, organizing the major themes scholars have used. We also differentiate between two perspectives researchers can employ: (1) misbehavior as deviance and (2) misbehavior as a wider construct. Findings - Marketers generally overlook consumer misbehavior and put the cost down as that of running a business. Furthermore, they are burdened by the notion of customer sovereignty which is the dictum that "customers are always right." But customers also lie, cheat, steal, harass, and abuse. Consumer misbehavior is thus multifaceted which in turn makes the definition difficult to pin down. After reviewing the many definitions of consumer misbehavior, including cyber misbehavior, the authors concluded that the disruption perspective is more managerially useful than the perspective based on violation of norms. This is because disruption of the business is not only harmful or unlawful but can lead to a loss of well-being, material resources, and reputation of individuals and/or organizations. Implications - The chapter proposes a Pre-di-post framework that can be used to deal with customer misbehavior. Originality/value - Most marketing scholars have focused primarily on misbehavior as deviance, yet this limits the kinds of problems one tends to focus on and the range of solutions one normally considers. We offer an alternative perspective where misbehavior may be instead "an unremarkable consequence of normal conditions" which may suggest a wider range of amelioration strategies.