The authors tested the effectiveness of a mindfulness-based program in reducing sport-injury incidence. A total of 168 young male elite soccer players were randomly assigned to mindfulness and control groups. The mindfulness group consisted of seven sessions based on the mindfulness-acceptance-commitment approach, while the control group consisted of seven presentations on sport-injury psychology. Athlete exposure and injury data were recorded during one season. State and trait mindfulness, sport anxiety, stress, and attention control of participants were assessed. Number of injuries, average of injuries per team, and days lost to injury in the mindfulness group were significantly lower than those in the control group. Mindfulness and attention control were lower and sport anxiety and stress were higher in injured players than in noninjured players. Psychological variables were associated with injury. Mindfulness training may reduce the injury risk of young soccer players due to improved mindfulness and attention control and reduced sport anxiety.