Successful treatment of addictive behaviors is difficult because of the complexity of relevant contributing variables. Restricted environmental stimulation therapy (REST) is offered as a useful, flexible tool that can facilitate change in addictive variables at each level of complexity, from habitual acts through attitudes to self-concept and spirituality. The nature of REST is discussed in terms of processes and effects. Basically two processes, refocusing and rebalancing, contribute to the various physical and mental effects of restricted environmental stimulation. These effects include profound relaxation, relief from pain, and a shift in consciousness to a state that is more introspective, less defensive, and more receptive. Research in treating addictive behaviors with REST is reviewed with smoking, overeating, alcohol consumption, and drug misuse. There is a substantial body of literature demonstrating the effectiveness of REST in modifying smoking behavior. Very little research has been done on REST and drug misuse. Each of the other areas has a small number of preliminary studies that suggest REST as a promising treatment. In general, chamber REST proves to be effective in facilitating attitudinal and behavioral change, and maintaining those changes. The scant research with flotation REST show it to be less effective in modifying behavior but more relaxing and pain alleviating than chamber REST. The characteristics of the REST experience that make it effective in treating addictions are discussed as follows: (1) the induction of a general relaxation response, (2) substance misusers find serenity and relief by nonchemical means, (3) internal refocusing to concentrate on personal problems, (4) disruption of habits through removal of trigger cues and response possibilities, (5) increased feelings of control over addictive behaviors, and (6) enhanced learning processes. REST is a versatile, cost-effective treatment modality with demonstrated effectiveness in modifying some addictive behaviors and promising applications with others.