This article presents an evaluation of the effectiveness of an applied mindfulness intervention for stress reduction delivered to Paralympic leaders prior to the Paralympic Games. The intervention group of Swedish Paralympic leaders (n=10) received a mindfulness intervention of eight web-based seminars, while a Norwegian reference group (n=6) received no intervention. Three assessments were performed for both samples: at baseline, post-intervention and six weeks post-intervention. The evaluation indicated intervention effects of higher psychological flexibility (p=.03), less rumination (p=.02) and lower perceived stress (p=.001), and offers initial support for the applied usefulness of a web-based mindfulness training program as a supplement in stress-reduction programs for elite sport leaders. General challenges from an applied sport psychology perspective related to the implementation of mindfulness interventions in samples with experienced high levels of stress and perceived time-constraints are discussed.