The present research focuses on the question whether spirituality, religiosity and maladaptive personality traits, as measured by the PID-5 (antagonism, psychoticism, disinhibition, negative affectivity, detachment), predict epistemologically unfounded beliefs (conspiracies, pseudo-science and paranormal beliefs). The sample included 829 participants recruited through social networks (58% women, mean age 29.98 years). The results showed that especially psychoticism is a positive predictor of all types of epistemologically unfounded beliefs (EUB). Spirituality and religiosity predicted only paranormal beliefs with very small effect size. No interaction between psychoticism and spirituality/religiosity in prediction of EUB was found. Results confirmed that some maladaptive personality traits (especially psychoticism) can play a significant role in EUB and should be taken into account when considering sources of EUB at the individual level.