Liriano agreed to a two-year contract with the Pittsburgh Pirates on December 21, 2012. The contract was voided shortly after as he suffered an injury to his non-throwing arm and failed his physical, having broken his non-throwing arm while he tried to scare his kids at Christmas. A new two-year deal was reached between the Pirates and Liriano and became official on February 8, 2013. He started the 2013 season on the Pirates's 15-day disabled list. He made his debut on May 11 against the New York Mets. Liriano's improved command by changing his pitching mechanics led to a career rebirth with Pittsburgh. He finished his 2013 campaign with a record of 16–8, an ERA of 3.02, and 163 strikeouts.