Gushnaspdad first appears in 496, as one of the supporters of Balash. After Balash's accession, Gushnaspdad urged the Sasanian noblemen to execute Kavad, the brother of Balash. He is reportedly said to have told the Sasanian noblemen while holding a knife: "You see this knife, how extremely small it is; nevertheless it is able at present time to accomplish a deed which, be assured, my dear Persians, a little later two myriads of mail clad men could not bring to pass."
However, the Sasanian nobles declined the decision, and instead had Kavadh imprisoned; however, he later managed to escape and took refugee in Central Asia. In 498/9, Kavadh returned to Iran with the aid of the Hephthalites. Kavad then captured Ctesiphon, restored his rule, and had Gushnaspdad executed. Gushnaspdad was replaced by Adergoudounbades as kanarang.