Objectives: Mindfulness is a proven treatment in clinical settings. Our objective was to examine the feasibility and effect of a mindfulness-training program on the mental resilience and emotional intelligence of amateur basketball players. Methods: This was a parallel-group, pre- and post- test, randomised controlled trial. Thirty male amateur male basketball players from Tehran, Iran, were assigned randomly into experimental and control groups ( n = 15 each). Outcomes were measured using the mindfulness sport inventory, mental toughness (MT) questionnaire and emotional intelligence questionnaire. Data were analysed using ANCOVA and MANCOVA. Results: Mindfulness scores were significantly greater in the intervention group than in the controls following training. The intervention also increased overall MT and all of the component sub scores. The same applied to emotional intelligence and all of its components. Conclusions: These findings may have implications on sport mindfulness training in increasing the MT and emotional intelligence of athletes.