Pasayat started his career in litigation on 10 October 1968, when he was enrolled to the bar as an advocate.
In this role, he practiced before the Orissa High Court in taxation and constitutional matters while also taking up other commercial cases.
He was subsequently transferred and appointed the chief justice of Delhi High Court on 10 May 2000.
[1] Pasayat was elevated as a judge of the Supreme Court of India on 20 October 2001, and retired on 10 May 2009.
[1] Among the most notable of his decisions, he was the part of a constitutional bench of the Supreme Court which decided upon the constitutional validity of the reservation to 'other backwards classes' (OBCs) in national level institutions such as the IITs and the IIMs.