Hiding errors can undermine safety by amplifying the risks of undetected errors. This article extends research on occupational safety by investigating error hiding in hospitals and applies self-determination theory to examine how mindfulness decreases error hiding through authentic functioning. We examined this research model in a randomized control trial (mindfulness training vs. active control group vs. waitlist control group) within a hospital setting. First, we used latent growth modeling to confirm that our variables were related as hypothesized, both statically or cross-sectionally as well as dynamically as they evolved over time. Next, we analyzed whether changes in these variables were a function of the intervention and confirmed the effects of the mindfulness intervention on authentic functioning and indirectly on error hiding. To elaborate on the role of authentic functioning, in a third step, we qualitatively explored the phenomenological experience of change experienced by participants in mindfulness and Pilates training. Our findings reveal that error hiding is attenuated because mindfulness encourages a receptive view of one's whole self, and authentic functioning enables an open and nondefensive way of relating to positive and negative information about oneself. These results add to research on mindfulness in organizations, error hiding, and occupational safety. (PsycInfo Database Record (c) 2022 APA, all rights reserved).