The club's parent athletic association, A.S. Diagoras Dryopideon Aigaleo (Α.Σ. Διαγόρας Δρυοπιδέων Αιγάλεω) was founded in 1967. The founders have roots from
Kythnos which has the name Dryopis during the ancient times. The men's basketball section of the club was founded in 1996. After competing for many years in local and regional leagues in Greece, Diagoras Dryopideon played in a Greek national league for the first time, in the 2014–15 season, when the club competed in Greece's national
minor league, the
Greek 4th Division. During the 2016–17 season, Diagoras won the Greek 4th Division's 2nd Group, and thus earned a
league promotion to the
Greek 3rd Division, for the following 2017–18 season. Diagoras finished second in the Greek 3rd Division's 1st Group, in the 2017–18 season, and thus earned a league promotion to the
Greek 2nd Division, for the
2018–19 season. The club also made it to the last 16 stage of the
2018–19 Greek Cup tournament, where they lost to
AEK Athens, by a score of 76–54. In the
2019–20 Greek Cup tournament, Diagoras made it to the semifinals of the Greek Cup, where they again lost to AEK Athens, by a score of 89–71. In the Greek 2nd Division's
2019–20 season, Diagoras finished in second place in the league, behind
Charilaos Trikoupis, and earned a league promotion up to the top-tier level
Greek Basket League, for the following
2020–21 season. However, Diagoras declined to take their place in the league. ==Arena==