A growing body of research suggests that mindfulness, a receptive attentiveness to one’s present moment experiences, has the potential to adaptively regulate habitual behaviors. No prior study has tested the effect of mindfulness interventions on people’s daily desire experiences to inform the potential for adaptive desire regulation. The present exploratory randomized controlled trial examined the effect of a 14-day smartphone-based mindfulness intervention (versus a coping control intervention) on the frequency, intensity, duration, and enactment of everyday desires in 19 participants. The desire domains included basic need-based desires (i.e., for food, drink, sleep) and secondary desires (e.g., for sex, media, social interactions, work), assessed for 7 days pre- and post-intervention through ecological momentary assessment (EMA). Emotion data collected alongside, also through EMA, permitted examining the role of the mindfulness intervention in altering a potential link between experienced emotion (positive and negative) and desire. Results showed that intervention condition significantly predicted post-intervention desire frequency; those in the mindfulness condition experienced a higher frequency of desires post-training, and specifically, increased secondary desire frequency, but not basic desire frequency. Intervention condition did not predict the other desire outcomes (enactment, strength, or duration). Results also revealed that intervention significant moderated the association between positive emotion and overall desire frequency; those in the mindfulness condition experienced fewer desires when experiencing increased positive emotion, whereas there was no association between positive emotion and desire after coping training. Intervention condition did not moderate associations between positive emotions and other desire variables, or negative emotions and any desire variables.