There is now and may always be a difference of opinion on the advisability of contact sports for the younger and usually more immature boys. It is said by some that the many and varied experiences and attitudes gained through early participation in team contact sports greatly over-balances any detrimental effects which might occur. The other point of view expresses the opinion that anything which is gained at this younger age can and will be better accepted. when there is less chance or physical, mental, and social strain or damage. The age groups considered ln this study are usually exempted from the above discussion. High school boys, with some limitations, are felt to be mature enough to compete in these activities. However, the maturity of many ninth and tenth grade boys can be questioned. In any case, competitive athletics for all high school boys is a firm part of the school program and continuous effort should be made to improve the conditions which surround it. It was the purpose of this study to show the physical affects of the contact team sport of football on two classes of boys. The comparison was made between ninth and tenth grade boys and eleventh and twelfth grade boys, all of whose injuries were obtained during practice for or actual participation in interscholastic competition in high school football.