In 1180 when Prince Mochihito was raising an army, Yoshikiyo mobilized together with MINAMOTO no Yorimasa, and after Yorimasa was defeated he joined the troops under the command of MINAMOTO no Yoshinaka.
治承4年（1180年）の以仁王の挙兵に際しては源頼政と行動をともにし、頼政が敗死した後は源義仲の麾下に走る。