Introduction <p>The notion that the moon exerts an influence on human behavior has long been a topic of interest. A number of studies have been conducted, yielding results that are, at least in part, contradictory. In this context, the objective of this study is to examine the impact of the lunar cycle on psychiatric emergency consultations.</p> Methods <p>This retrospective study analyzed 69,764 psychiatric consultations at the Centre Psychiatrique d’Orientation et d’Accueil, one of the largest psychiatric emergency departments in France, between 2016 and 2023. The data set comprised age, gender, reasons for consultations, diagnosis, disposition at the end of the consultation and lunar phases. The data were analyzed using four operational definitions of lunar exposure to ensure comparability with previous studies.</p> Results <p>No statistically significant correlation was identified between the phases of the lunar cycle and the number of consultations or hospital admissions. No trend was observed in relation to reasons for consultations or specific psychiatric disorders, regardless of the definition used.</p> Conclusion <p>The results confirm no significant influence of the lunar cycle on psychiatric emergencies, in line with the majority of existing studies. Despite popular beliefs, the study suggests that the moon has no effect on the number of emergency room consultations or the nature of psychiatric disorders, reinforcing the idea that such beliefs are scientifically unfounded at least at population level.</p>