Aim: The purpose of the study was to investigate the effect of Official basketball competition on the levels of Cortisol and Immunoglobulin A among pre pubertal girls of 10-11 years old. Method:The statistical population of the study consisted of 12 female basketball players with an average age of (10.58 0.15 years).Collection of the salivary specimen was conducted in accordance with the standard procedures, before and immediately five minutes after the competition. Cortisol concentration and Salivary IgA level were measured, using ELISA quantitative method. Statistical analysis was conducted using the dependent t-Test.Results: the results revealed that an official basketball competition increases cortisol and salivary IgA concentrations, significantly (p ≤ 0.00).Regarding the results of the analysis, one may conclude that sport competition is likely to affect physiological responses of the children and juvenile's immune systems. Conclusion:It worth to note that despite widespread participation of children and juveniles in competitions and sport events, little researches have been conducted on their immunological factors and stress hormones in response to stressful conditions dominated over the competitions and sport events. Even insufficient information and data achieved through investigations are necessary and useful in evaluation of this age group, concerning their hormone responses to the competitions and sport events.