In scientific literature, active commitment to a religious community is considered to be a protective factor against suicidal behavior. However, it is assumed that this protective effect does not apply to 'reformed pietists' or strict Calvinists, an orthodox-protestant group in the Netherlands.<br/> AIM: To explore whether the incidence of suicide is higher among reformed pietists than among other Christian patients of Eleos, a Dutch christian institute for mental health care.<br/> METHOD: A retrospective cohort study was conducted over the period 2000-2017. All evaluating reports, which were written after a suicide, were analyzed.<br/> RESULTS: In the period 2000-2017 28 evident suicides were committed. The number of suicides among reformed pietistic patients was about 10 times lower than among other Christian patients.<br/> CONCLUSION: The assumption that reformed pietists run a relatively high risk for suicide does not have adequate grounds. In case of risk assessment, reformed pietistic affiliation might be considered to be more a protecting than a risk-increasing factor for suicide.