In 1960–61, Phivos won the B1 league of Athens Football Clubs Association and Dedes was one of their main scorers.
At the age of 17 he was discovered by Panagiotis Pallas of Panionios and he was recommended to the technical director of the team, Thanasis Papathanasiou.
Two months later, the coach of the team, Ioannis Skordillis and Nikos Zakardis gave him the chance to play for the first time against Fostiras.
[5] He helped his team take the win in the derby against Panathinaikos at home by scoring a goal in the final 4–3, on 20 April 1975.
In three years of playing for AEK Athens he once more became the top scorer of the league in 1976 with 15 goals,[7] while the following season, he was a member of the squad that reached to the semi-finals of the UEFA Cup.
[9] In 1962, Dedes was called to Greece U18, for which he played in two matches against Turkey, a 1–0 defeat in Athens and 1–0 win in Smyrni where he was the scorer in the 18th minute.
With a 2–1 victory in Athens and a 1–1 draw in Ankara, Greece managed to qualify for 1963 UEFA European Under-18 Championship in London.
His first goal for the tournament was in a historical 2–1 victory against Portugal on 11 December 1968 in Karaiskakis Stadium and the second was in a 2–2 draw against Romania on 16 April 1969 with Dedes taking the lead for Greece.
He was nephew of the legendary goalkeeper of AEK Athens, Christos Ribas, and his elder brother, Kostas played for Pannafpliakos.