From ST Xavier’s College he studied English and later at the University of Calcutta. He then became a professor at St. Xavier's College and served there for over four decades. A friend of Fr Robert Antoine, he had himself longed to be a Jesuit when young, and that cursed his entire work and life. Purshottama. Lal was a noted Professor of English at St. Xavier's College in Calcutta. He served as a Special Professor of Indian Studies at Hofstra University for a year in early 1960s and thereafter he held Visiting Professorships at many universities and colleges throughout America.
Under the name of P. Lal, he penned down over a dozen volumes of literary criticism, eight books of poetry, a biography, various books of stories for children, as well as lots of translations from other languages, majorly Sanskrit, into English. He also assembled a number of literary anthologies. He was conferred the distinguished Jawaharlal Nehru Fellowship in 1969. He was best known for translating the entire Indian epic poem Mahabharata in English.
He tied knots with Shyamasree Devi in 1955, and the couple was blessed with a daughter, Srimati Lal and a son Ananda Lal.
Purushottama Lal breathed his last on 3 November, 2010 in Kolkata, India.