Balachandra Rajan was a scholar of poetry and poetics. He was Fellow of Trinity College, University of Cambridge, 1944–8. He was the editor of a series of slim volumes on literary criticism titled Focus which had at least four issues between 1945 and 1948 and was published by Dennis Dobson. The series had its beginnings at Cambridge, where Rajan co-edited (with Wolf Mankowitz) a collection of criticism titled Sheaf which was published by the university, and authored his own collection of poems, Monsoon and Other Poems. While in Britain, he also contributed poems to literary journals, including Life and Letters Today and Poetry London (indeed he was possibly the only South Asian to contribute to the latter, with the exception of its editor, Tambimuttu). Focus appeared to engage critically with work by some of the big literary names of the day, including Huxley, Sartre, Isherwood and Kafka. Contributors of essays include Kathleen Raine, D. S. Savage and Julian Symons, with poems by e. e. cummings, George Barker, John Heath-Stubbs and Vernon Watkins, as well as Rajan himself.

In 1948, Rajan left England for India where he served in the Indian Foreign Service until 1961, working also with UNESCO, UNICEF and as part of the Indian delegation to the United Nations. Later, he returned to academia, initially at the University of Delhi, before taking up a post at the University of Western Ontario, Canada. Best known for his work on Milton, Rajan completed a critical book on Paradise Lost as well as an edition (with introduction and commentary) of this canonical work. He also wrote on Spenser, Yeats, Marvell, Eliot, Keats and Macaulay, and completed two novels.