The aim of this research project was to evaluate the influence of exclusion as a harm-reduction intervention on parameters such as gambling behavior, motivation to seek help and several well-being measures. Gamblers, who were excluded from both land-based and online Swiss casinos, completed a written questionnaire three times, at six-month intervals. To identify possible changes due to the exclusion, gamblers who were not excluded were also surveyed. Of the 242 respondents, 55.0% (n = 133) were not banned at any time, 13.6% (n = 33) were excluded at the time of the first survey wave and remained so, while 31.4% (n = 76) of respondents were excluded for a minimum of one wave. The present study highlights the influence of exclusion on gamblers’ well-being. A repeated-measures ANOVA revealed considerable improvements for the excluded gamblers with respect to the parameters of mental health, general well-being, satisfaction with finances, and severity of disordered gambling behavior. The results demonstrate that exclusion has an impact not only on reducing gambling-related harm and mental health problems but may also positively influence well-being. Alongside parameters such as the individual`s financial circumstances and severity of gambling disorder, well-being parameters should be considered within the exclusion processes and further harm reduction measures.