Objectives Mindfulness-based interventions in the context of sports have been shown to result in higher mindfulness scores and improved physiological and psychological parameters. The goal of this pilot study was to investigate the effects of a newly developed seven-session mindfulness-based intervention, mindful emotions, on German tennis players.

Methods The study was conducted in a pre–post test design with an intervention and a control group. Before and after the mindfulness-based stress reduction training the following dependent measurements were assessed: athletic performance (serve accuracy) and psychological performance indicators (mindfulness, stress and competition anxiety).

Results The results indicate a better performance of the intervention group for the difference scores between post-test and pre-test in one of the sport-related anxiety factors, the concentration disturbances index.

Conclusion In order to further investigate the effects of this mindfulness-based intervention in competitive sports, additional studies with a larger number of participants have to follow.