The current study examined the effects of a brief mindfulness induction on overselectivity. Participants were randomly assigned to a mindfulness, unfocused attention (relaxation), or no-intervention group. Participants experienced their designated intervention for 10 min, and they underwent simultaneous discrimination training (AB+ CD-) followed by an extinction test (AvC, AvD, BvC, and BvD). Levels of mindfulness were measured by the Toronto Mindfulness Scale, and participants were asked about their previous experience with mediation and mindfulness practice. Mindfulness reduced overselectivity, and previous levels of mindfulness experience identified by a single question moderated this effect, with mindful-experienced participants showing less overselectivity. Both findings have some practical utility in the ongoing investigation of the possible use of mindfulness in medical settings.