In 1985, he gets accepted at the Athens School of Fine Arts, to study sculpture with professors G. Nikolaides and T. Papagiannis. He also attends the plaster, pottery, woodwork and metalwork Studios.

In 1990, he completes his studies, receiving his Degree in Sculpture with full marks. Stelios Gavalas then lives and works in Sydney Australia (1992-1994), where he cooperates with the School of Arts in Sydney and experiments with various materials in his work.

Since 1998, he works for the Archeological Receipts Fund of the Ministry of Culture, where he became Artistic Manager, in 2006. He has, also, worked for the Acropolis Restoration Service and he also collaborating with the Byzantine Museum, the Archeological Museum and the Numismatic Museum, where he creates molds, out of original ancient works of art. He received the Sculpture Award, for his participation in the Biennale Florence 2001.

Stelios Gavalas has conducted 8 solo exhibitions in Greece and participated in many group exhibitions in Greece and abroad.