Valavanidis's origin is from Alexandroupoli and was raised in the local club of Feres, Evros.

Valavanidis was member of the team which won the Saporta Cup 1991, at the age of 17.

He played with PAOK, until 1994 and he won the Greek League championship in 1992, and FIBA Korać Cup in 1994.

He also played at the 1992 FIBA Europe Under-18 Championship, in which his team finished in fourth place.

Valavanidis died from a heart attack in Thessaloniki, on 12 November 2024, at the age of 50.