The relationship between involvement in ECA, academic achievement and self esteem was studied in the research paper. The sample included 141 middle and high school students selected from 2 middle SES schools in Greater Beirut. The findings of the ANOVA and t-test suggest that there is a statistically significant difference in the academic achievement of participants in moderate hours of ECA (10-15 hrs/week) compared to low (0-9) or high (16+) participation in ECA. Additional results suggested that self esteem among the three groups was insignificant. Moreover the outcomes revealed that ECA related to sports had greater impact on the academic performance of students than non sport ECA. However, males were the most influenced when it came to sports. Further longitudinal research can be done to identify the long term effect of these ECA on students. The number of ECA can be complementary study as well.