Abstract: The aim of the study was to assess the effects of a mental training program on Scuba diving performance. 20 participants enrolled in junior open water diving courses served as anticipants. Method: in Scuba diving program (13-14year) in summer 2019. Each group (n=4). In addition to scuba training, received. The intervention group reported different significant between pre and post test scores for: Sport Mental Training Questionnaire – SMTQ, Trait Sport –Confidence Inventory (TSCI), and the Athletes Perception of Quality of Performance During practice (APQP), and some of SCUBA Skills. Control value for each parameter was calculated as an average value mean and standard deviation ±SD. Results: scores post-test Significates for Psychological characteristics performed better on Scuba Skills: in the questions (Q12) Whenever I lose my self-control during a competition, I can regain control of my own actions in the right moment (P=9.1*).(Q2) I use self-talk to improve my actions, focusing my attention on key-elements of performance (technique, tactics, body sensations)(P=6.85*).(Q17)I use mental imagery to control my own emotions(P=6.69*). significant differences in Test of Trait Sport –Confidence Inventory (TSCI)For junior Scuba Divers in the following questions (Q1) Compare your confidence in your ability to implement the skills to be successful for the most trusted athlete you know. (P=8.64*), (Q8) Compare your confidence in your ability to be successful for the most trusted athlete you know. (P=7.58*), (Q13) Compare your confidence in your ability to bounce back from poor performance and succeed in the most trusted athlete you know. (P=5.67*). significant differences in Test of Scuba diving skills We found significant differences in Test of Scuba diving skills for junior Scuba Divers in the following tests and evaluation in the following tests:(Q20) Buddy breathing stationery and swimming (donor and receiver) (p=9.37*),(Q11) Fin pivot (neutral buoyancy)(P=9.14*).Conclusion: Pre-performance mental visualization and psychological tests are a process of transition from non-performance-related conditions to performance-related conditions directly to link the movement vocabulary and the overall visualization of underwater motor skill. This improves the level of skill performance and increases the speed of acquisition and learning skills and gives the diver More confidence under water and the ability to get rid of the wrong performance that causes the crises and pressures of the performance of skilled diving. during Mental training improved psychological skills to enhance junior scuba diving performance.