Objectives <p>Approximately one-fifth of the European population suffer from chronic pain. Mobile-based interventions have the potential to target (sub-)acute pain on a global scale and help prevent it from becoming chronic. This randomized controlled trial investigated the effects of a mobile-based mindfulness intervention (provided via the <i>7Mind</i> application; 7Mind GmbH, 2021) in the secondary prevention of chronic pain. We evaluated whether this intervention can improve physical health, positive affect, optimism, mindfulness, and self-compassion in subclinical participants.</p> Method <p>Participants (<i>n</i> = 369) were randomly assigned to an experimental (mindfulness-based intervention), active control (progressive muscle relaxation), or passive waitlist control group. The interventions were delivered by the same application. Of the participants, 264 completed the posttreatment assessment (2&#xa0;weeks) and 185 the follow-up measurement (3&#xa0;months). We used hierarchical linear modeling to analyze our data.</p> Results <p>The experimental group demonstrated significant increases in all outcome variables except for mindfulness directly after the intervention. Additionally, improvements in the experimental group were superior to changes in the waitlist group; this was not observed for the active control group. However, only mindfulness and self-compassion exhibited long-term superiority. With respect to physical health, while the experimental group yielded timely recovery that remained stable until follow-up, long-term, this was not superior to the recovery of participants in both control groups.</p> Conclusions <p>Our findings suggest that mobile-based mindfulness interventions have the potential to facilitate early recovery from acute pain. However, long-term effects are limited. Further research is required to investigate the maintenance of treatment effects.</p>