Meditative insight has been defined in previous research as a process of cognitive change based on the understanding through personal experience of the fundamental Buddhist concepts of impermanence, suffering, not-self, and emptiness. It has been proposed that the construct of insight represents an important mechanism in meditative practices, and an instrument for its assessment has recently been proposed. Building on previous findings, this study was designed (1) to test the psychometric properties and perform a validation of a French version of this instrument and (2) to explore the relationship between meditative insight and perceived stress through mediation of irrational beliefs. Self-report data were obtained from a sample of French-speaking meditation practitioners (N = 260). The results confirm the validity and the reliability of the French version of Ireland's Insight Scale (2012), and partially support the hypothesis of the relationship between meditative insight and perceived stress being mediated by irrational beliefs.