The purpose of the Delaware Interscholastic Athletic Association (DIAA) is:
- to preserve and promote the educational significance of interscholastic athletics;
- to ensure that interscholastic athletics remain compatible with the educational mission of the member schools;
- to provide for fair and equitable competition between the member schools;
- to promote sportsmanship and ethical behavior;
- to establish and enforce standards of conduct for athletes, coaches, administrators, officials, and spectators;
- to protect the physical well-being of the athletes; and
- to promote healthy adolescent lifestyles.
The DIAA is designated by the Secretary of Education to regulate and oversee the conduct of interscholastic athletics in the state of Delaware.
From 1947 to 1966, interscholastic athletics was governed by the Delaware Association of Secondary Administrators (DASA). In 1966, DSSAA was formed because the growth of interscholastic athletics necessitated a separate governing body.
In July 2002, DSSAA was dissolved and DIAA took its place with the same goals, objectives and responsibilities.
The membership consists of 118 school (61 high schools and 55 middle schools). Of the sixty-one high schools, twenty-four are traditional public, twelve are charter six are vo-tech and nineteen are private. Of the fifty-five middle schools, thirty-one are traditional public, twelve are charter, and twelve are private.