The purpose of the work is to study the role of mindfulness and self-compassion in the mental preparation of federated chess players. A cross-sectional study was carried out on 123 players using a battery of self-administered online questionnaires. Significant relationships were found between the chess strength of chess players and the overidentification and common humanity subscales, corresponding to self-compassion construct, and between the years practicing mindfulness with the mindfulness awareness subscale, self-compassion, the depression subscale and the depression-anxiety-stress construct. The structural equations model shows the positive relationship between mindfulness and self-compassion, the importance of self-compassion as a mediating variable between mindfulness and the depression-anxiety-stress construct, and a significant relationship between depression-anxiety-stress construct and sleep difficulties. The significance and novelty of the work lies in being the first study in which these relationships and the structural model are established in the field of sport.