Extending prior research on perfectionism and religiosity, the current study investigated their relation among Latter-day Saints (LDS)–also known as Mormons–through a sequential mixed-methods design. An online community sample of 194 LDS completed the Religiousness Measure-Revised and the Hewitt Multidimensional Perfectionism Scale. Subsequently, six of these participants were interviewed to further explore how perfectionism manifests among Mormons in a qualitative pilot study. Quantitative results demonstrated significant positive correlations between religiosity and perfectionism, but only for self- and other-oriented perfectionism. Qualitative content analysis indicated further how adaptive and maladaptive perfectionism manifest in an LDS context. Implications for culturally competent practice and future research are discussed.