This study was designed to test the hypothesis that events such as the Christmas Eve Carol Services at Liverpool Cathedral that include some regular churchgoers (people who attend services most weeks) and much larger numbers of occasional visitors (who may attend church only once or twice a year) make a significant impact on the psychological health and well-being of the participants. Using a repeat-measure design, participants were invited to complete a copy of the Oxford Happiness Questionnaire while they were waiting (...) for the service to begin and then to complete a second copy during a five-minute organ improvisation just before the close of the service. Data provided by 802 participants who completed both copies of the instrument demonstrated a significantly higher score on the Oxford Happiness Questionnaire at time two than at time one, suggesting that attendance at the service had exerted a positive impact on psychological health and well-being. Contribution: Situated within the science of cathedral studies, this article demonstrates by means of a repeated-measure study that cathedrals can make a significant impact on the psychological health and well-being of the wider community served by them. The same well-being measure was completed by 802 participants at the Christmas Eve Carol Services before and after the event, with a significant increase in scores at time two. (shrink)