The France centre-back brought up the double century in English league football as he started for the Gunners in their meeting with Swansea
Laurent Koscielny has made his 200th Premier League appearance for Arsenal after starting in the meeting with Swansea City on Saturday.
The France international has clocked up a total of 274 games for the Gunners in all competitions, with a double century having now arrived in England's top-flight.
Koscielny joined the north London club from Lorient back in 2010 and has developed into one of Europe's top central defenders.
The 31-year-old is an ever-present in Arsene Wenger's starting XI and put pen to paper on a new contract with the Gunners on Thursday, taking him through to 2020.