The last 20 years have seen a significant paradigm shift in how we view alcohol misuse. The dichotomous model of "alcoholism" and "normal drinking" has now been replaced by the concept of a spectrum of disorders. In this new framework, "hazardous alcohol use" is defined as a repeated pattern of drinking that confers the risk of harmful consequences. It is a typical example of a subthreshold disorder. Where actual physical or psychological harm or social problems have occurred, the terms "harmful alcohol use" and "alcohol abuse," respectively, are applied. These conditions would typically be considered to be above the clinical threshold. The most severe disorder, alcohol dependence, is a psychobiological syndrome with often severe physical, psychological, and social sequelae. This article describes how the concept of hazardous alcohol use originated, and reviews the intervention techniques that have been developed to induce and assist hazardous drinkers to reduce their consumption to nonhazardous levels. The findings from a series of World Health Organization (WHO) collaborative studies on brief interventions for hazardous alcohol use are described. This work has resulted in the development of the Alcohol Use Disorders Identification Test (AUDIT) screening instrument, which can detect over 90% of hazardous drinkers in a range of settings, and the demonstration that 5 minutes' structured advice can reduce hazardous consumption by 30%. The later phases of this program of work have examined strategies to promote the dissemination of brief interventions for hazardous alcohol use throughout primary health care, and the nationwide, systematic, and sustained utilization of these interventions.