Born in 1436 as the son of Imagawa Norihata, 6th head of the Suruga Imagawa clan. During the Kyotoku Disturbance (1454) he marched as far as Kamakura, distinguishing himself in the campaign against Koga Kubo Ashikaga Shigeuji and receiving a commendation from the 8th shogun Ashikaga Yoshimasa. In 1461 he succeeded to the Suruga shugo post, and when the Onin War broke out in 1467 he sided with the Eastern army. His principal wife, Kitagawa-dono, was the daughter of Ise Moritada and sister of Ise Sozui (the later Hojo Soun); their son, the heir Ryuoumaru (later Imagawa Ujichika), was born in 1473. In 1468, at the request of his ally Hosokawa Katsumoto, he returned to Suruga and actively pushed into Totomi Province, repeatedly fighting the Totomi shugo Shiba clan and its local vassals. In 1476, he led 500 mounted men to subdue the Totomi vassals Yokochi Shirobei (lord of Yokochi Castle) and Katsumata Shurinosuke (lord of Katsumata Castle), who had rebelled and allied with Shiba Yoshitada; he captured both castles and killed both men. But on the return march, at Shiokaizaka in Totomi (present-day Kikugawa, Shizuoka), he was ambushed by remnants of the Yokochi and Katsumata forces and killed by a stray arrow. He was 41. His heir Ryuoumaru was still a child, and a succession dispute arose within the Imagawa house, but it was settled through the guardianship of his maternal uncle Ise Sozui (Hojo Soun); Ryuoumaru came of age as Imagawa Ujichika and laid the foundation for the later prosperity of the Suruga Imagawa clan.

A martially skilled commander who won distinction campaigning as a young man in the Kyotoku Disturbance and showed decisive energy in pushing into Totomi amid the chaos following the Onin War. Yet after subduing the Yokochi and Katsumata, he apparently let his guard down on the return march and was fatally ambushed — a hasty aftermath that proved his undoing.

Yoshitada's conquest of Yokochi and Katsumata Castles and his death at Shiokaizaka mark, in the local history of Totomi, a symbolic episode of both the expansion and the setback of Imagawa power in the region. Ise Sozui (Hojo Soun), his brother-in-law, who resolved the succession dispute triggered by Yoshitada's sudden death, used the episode to establish a foothold in Suruga as the Imagawa house's guardian, laying the groundwork for his own later rise as an independent Sengoku daimyo. Yoshitada's son Ujichika greatly expanded Imagawa power, and his grandson Imagawa Yoshimoto grew into the daimyo renowned as 'the finest bowman on the Tokaido.'