He had varied research interests, including the study of medicinal plants.
He participated in a large study of cancer incidence in India.
He was key in founding pharmaceutic education at the University of Punjab in Lahore.
The initiation of pharmaceutical education in Punjab of undivided India was in 1944, when in King Edward Medical College at Lahore Dr. Khem Singh Grewal thought of starting the B. Pharm.
Dr. Grewal who was Professor of Pharmacology in the medical college had been in association Col. R. N. Chopra at School of Tropical Medicine in Calcutta (now Kolkata) and with Dr. J. H. Burn at the London School of Pharmacy.