The present study was intended to be a methodologically sound test of the efficacy of three stress management interventions for the purpose of prevention. The long-term impact of several comprehensive stress management interventions was compared on the aspects of coping ability being targetted by the programs, stress, and the adverse effects of stress. Subjects were asymptomatic male business managers and supervisors. Effects of stress were measured by multiple outcomes including psychological and physical health, and work-related variables. Two intensive training programs, cognitive-behavioural coping skills training, and aerobic-exercise and fitness training, and a practically oriented brief-intervention educational program were compared. Methodological problems of past research were addressed, including systematically choosing the comprehensive list of measures and the interventions on the basis of an understanding of the process of stress, and evaluating the maintenance of effects over a one-year period after the interventions. The findings of a single repeated-measures statistical test demonstrated an ameliorative effect after the treatment period for all three interventions on coping skills, cognitive behavioural coping efficacy, subjective stress, quality of life, and an index of physical health. The effects were maintained with coping skills both six months and one year later, and with the physical health measure one year later. The mechanism of the effects over time cannot be stated definitively, although it seems reasonable to suggest that the observed impact resulted from some common component of the treatment interventions, such as the information in the educational package, or the therapeutic expectation of change. Other possibilities are discussed. It seems that 10 weeks of training in these stress management techniques did not give any additional benefit to a two-hour comprehensive and practically oriented educational program. On the basis of the present results, as well as past evaluative research and the ultimate goal of primary prevention to reach the largest numbers of people possible, it is difficult to argue for the use of intensive stress management training with asymptomatic subjects. It seems that low intensive, low cost, and thus more accessible programs, such as the educational intervention in the present study, may be more appropriate for the purpose of primary prevention.