Career
As a player, Vlachos played for Olympiacos from 1989 to 1998, winning numerous titles. After his retirement, he became assistant coach of Olympiacos under coaches Dragan Matutinović, Zoltán Kásás and Veselin Đuho. He became Olympiacos head coach in 2011, following a successful stint as head coach in Palaio Faliro.
In 2014, he became head coach of Greece national team, whom he led to the bronze medal at the 2015 World Aquatics Championships in Kazan.