Improving the long-term psychological health of the population is an ambitious but consistent goal in the National Service Framework for Mental Health (MHNSF). Large-scale self-referral psycho-educational Stress workshops, run in one geographical area for members of the general public, had been shown to be effective and to reach those who had not consulted their GPs about their stress problems. A key aim of this study was to explore whether this workshop format, which may help achieve the MHNSF goal, can be generalizable to other areas of differing deprivation. We compared outcome and levels of take-up of Stress workshops run in three geographical areas, differing in degrees of deprivation, as well as characteristics of self-referrers, including baseline scores, sociodemographic details and treatment-seeking patterns. In all three areas, experimental group participants showed less anxiety, stress and distress at 3-month follow-up compared to waiting list control group participants, with no geographical differences in effectiveness. No differences in initial stress and anxiety scores were found. GP consultation rates varied between 50–72%, with the highest consultation rates in the most deprived area. Surprisingly, enquiries about workshops correlated negatively with area deprivation indices. Some sociodemographic differences were found. A certain amount of self-selection for these workshops seems to have occurred; this may be a function of help-seeking for psychological help in deprived areas being different to that in less deprived areas. Nevertheless, large-scale Stress workshops have been found to be equally effective for those who self-referred in areas differing in deprivation, reaching people with stress problems who may not have consulted their GPs. While they did not reach all groups of people, they may have the potential to help improve the psychological health of the population.