In 2012-13 Cosgrove scored 784 runs at 39.20 in the Sheffield Shield, the second-highest total in the competition behind Tasmanian teammate Ricky Ponting. He was less successful in limited-overs cricket, scoring just 51 runs in 4 games in the Ryobi Cup and 61 runs in 5 Big Bash League games, where he played for Sydney Thunder.
