On 4 January 2012 Bertāns signed a three-and-a-half-year contract with the Serbian club Partizan Belgrade. In the game against Red Star Belgrade in June 2013, he has torn ACL on his right knee which sidelined him off the court for 9 months. He returned to the court in a mid-March game against Maccabi Tel Aviv, helping his team to get a win. On 28 March 2014 Dāvis scored 20 points in a road Euroleague game vs Lokomotiv-Kuban. Partizan ended season winning its 13th and Dāvis third consecutive Serbian League title defeating arch rivals Red Star Belgrade with 3-1 in the final series. On 3 July 2014, Bertāns terminated his contract with the club.