As a risk factor of hallucination proneness, the level of mindfulness has not yet been investigated in non-clinical participants. Other potential mediators, such as mental distress (depression, anxiety, and stress) which contribute to hallucination proneness also need to be assessed. This study investigated the mediating effect of mental distress in predicting hallucination proneness based on mindfulness. A number of 168 Iranian university students completed three questionnaires: (1) the five-facet mindfulness questionnaire, (2) the depression, anxiety and stress scale; and (3) the revised hallucination scale. The results showed that there was a significant association between levels of mindfulness and hallucination proneness. Mental distress has a significant effect on four facets of mindfulness questionnaire and an insignificant effect on one facet (awareness) in predicting hallucination. These effects were both direct and indirect. The indirect effect was developed by the mediating role of mental distress.