Objectives <p>Both mindfulness and humor are inherently connected to well-being. Recent research found evidence for their combined effect in a joint training, the Humor-Enriched Mindfulness-Based Program (HEMBP). This study extends these findings by exploring (1) effects of Mindfulness-Based Stress Reduction (MBSR) on different forms of humor, (2) differential effects of the HEMBP on outcomes compared to MBSR, and (3) whether the HEMBP and MBSR may alter worldviews.</p> Method <p>Ninety participants were randomly allocated to three conditions: the HEMBP, MBSR, and a wait-list control group. Participants’ mindfulness, psychological well-being, life satisfaction, perceived stress, comic styles, and primal world beliefs (primals) were assessed before and after the trainings, and at 1-, 3-, and 6-month follow-ups. Changes in outcome variables over time were modeled by applying linear mixed-effects models.</p> Results <p>The HEMBP enhanced participants’ mindfulness, benevolent humor, psychological well-being, and life satisfaction compared to the wait-list control. Similarly, MBSR increased participants’ mindfulness and life satisfaction while reducing perceived stress and primal <i>good</i>, but no effects on humor were observed. Comparison between the two trainings revealed trends toward a greater increase in benevolent humor in the HEMBP group and a greater decrease in <i>good</i> in the MBSR group.</p> Conclusion <p>The results largely replicate previous research on the efficacy of the HEMBP. Both programs demonstrated similar effects on outcomes, with&#xa0;only the HEMBP increasing benevolent humor and psychological well-being, while MBSR reduced stress. Further research is needed to investigate qualitative aspects of the integration of humor in MBPs and the long-term impact of MBPs on individuals’ worldviews.</p> Preregistration <p>This study is not preregistered.</p>