He stayed for a while as army commander in Lu 魯, the mother state of Confucius, before he entered the service of Marquis Wen of Wei 魏文侯 (r. 424-387 BCE). Under Marquis Wu 魏武侯 (r. 386-371) he held the position of governor (taishou 太守) of the commandery of Xihe 西河.
The influence of Confucian thought was applied by him in practical government. Wu Qi advocated a relationship between ruler and minister characterized by mutual respect for each other, and for a benevolence of the ruler towards his subjects, like a father to his children. Such a goverment would contribute to the stability of the state. As a general he cared for the well-being of his troops and shared with them the hardships of the field service. The strength of the army of Wei should later be attributed to Wu Qi's paternal conduct towards his subordinates.
Later on, frictions with Marquis Wu caused Wu Qi to leave Wei and to enter the service of King Dao of Chu 楚悼王 (r. 401-381), who made him senior minister (lingyin 令尹). Wu Qi proved to be an excellent advisor for the king by suggesting him degrading third-generation descendants of the royal sidelines to commoners. The royal line was thus drastically strengthened and got rid of a lot of throne claimants and challengers of the central power. He also made the king dismissing useless officials and have an eye on the abilites of his ministers.
After a short time, King Dao could enlarge his territory by submitting the southern tribes of the "Hundred Yue" 百越 and attacking the smaller states of Chen 陳 and Cai 蔡 in the north. King Dao died soon, and the rebelling nobles killed Wu Qi. He is said to have been executed at the side of this patron, the king. King Su 楚肅王 (r. 380-370) had the rebels arrested and executed for having desecrated the body of his father.
Wu Qi was soon associated with other military strategists, mainly Sun Wu 孫武, and his name is often mentioned together with that of Sun.
There is a book Wuzi 吳子, which is normally attributed to Wu Qi. Except the 48 chapters long book Wu Qi 吳起 (the military treatise) in the imperial bibliography Yiwenzhi 藝文志 of the official dynastic history Hanshu 漢書, there is a short book Wuzi mentioned among the miscellaneous treatises in the same bibliography. It is not known if this is also a book by Wu Qi.