Bartzokas, a 2.00 m (6'7") tall power forward-center, made his senior level debut in the Greek 2nd Division (B) league, during the 1981–82 season.

Bartzokas' playing career ended at the age of 27, after he had suffered serious knee injuries to both of his legs.

Prior to his knee injuries, the Greek clubs AEK Athens and Olympiacos Piraeus had considered signing him.

After he retired from his playing career, Bartzokas first worked as a head coach in the Greek clubs Pefki, Vrilissia Basket, GS Kifissias, and OFI Irakleio.

With Maroussi, Bartzokas was a finalist of the European-wide third-level competition, the FIBA Europe League, in the 2003–04 season.

Prior to the 2006–07 season, Bartzokas signed on as the head coach of the Greek club Olympia Larissa.

Bartzokas then repeated the Greek League playoffs qualification with Olympia the next year, during the 2007–08 season.

[1] Under Bartzokas' leadership, Maroussi managed to qualify for the Top 16 Phase of the EuroLeague's 2009–10 season.

[2] Bartzokas became the head coach of the Greek club Panionios Athens, prior to the 2010–11 season.

Bartzokas became the head coach of the Greek EuroLeague club Olympiacos Piraeus, in June 2012, prior to the 2012–13 season.

On July 5, 2015, Bartzokas signed a 2-year deal with the Russian club Lokomotiv Kuban of the VTB United League and the EuroLeague.

On July 8, 2016, Bartzokas signed a three-year contract with the Spanish ACB team FC Barcelona.

[9] On June 30, 2017, Bartzokas returned to the VTB United League, in order to become the new head coach of the Russian club Khimki Moscow Region.

[11] On January 10, 2020, Barzokas returned to the Greek club Olympiacos Piraeus, after he signed a 2+1⁄2-year deal with them.

After two months as the club's head coach, the 2019–20 season was cancelled, due to the COVID-19 pandemic situation.