Chen Shi was mentioned for the third and last time in 229, during the reign of Liu Bei's son and successor, Liu Shan. He participated in the third of a series of military campaigns led by Shu's chancellor, Zhuge Liang, against Shu's rival state Wei. This is historically known as the Battle of Jianwei. Acting on Zhuge Liang's order, Chen Shi led troops to attack Wudu (武都) and Yinping (陰平) commanderies and conquered them for Shu. The Wei general Guo Huai attempted to seize back the two commanderies from Chen Shi, but retreated when he heard that Zhuge Liang had personally led an army from Jianwei (建威) to reinforce Chen Shi.