Founded in 1980, Panionios started its basketball section long after that, as it wasn't until 1982 when the team reached the Greek League. Before that, the club had reached the Greek Cup final in 1977. Panionios was among Greece's four best teams from 1984 to 1991 even when Aris stood on its way to lift trophies. It reached the Greek League Finals in 1987 and had third-place finishes in 1986, 1988 and 1990. Its efforts finally paid off in 1991 when Panionios won its first and only title to date, the Greek Cup. Panionios started to do well in Eurocup club competitions, reaching the Korac Cup semifinals in 1994. Panionios, led by Fanis Christodoulou, Henry Turner and Panagiotis Giannakis lost to eventual champion PAOK Thessaloniki. The club played the 1995-96 Euroleague and reached yet another European semifinal in the 1999 Korac Cup, but this time Barcelona stood in the way. Some underachieving years followed but a fourth-place finish in the 2004-05 Greek League allowed Panionios to play the then-called ULEB Cup. Panionios reached the 2005-06 ULEB Cup elimination rounds, losing against Aris in a double-overtime classic, and matched those results in 2006-07, losing against Valencia in the Last 32. Panionios was third in the 2007-08 Greek League, earning the right to play in the Euroleague. Despite wins against Efes Pilsen, Partizan or Real Madrid, Panionios did not go past the regular season. The club did not return to the Greek League semifinals until this season. Despite being swept by Olympiacos, Panionios bounced back to beat Kolossos in the third-place playoffs and earn the right to play the Eurocup for the third time in club history.