Sukh Dev is known to have been involved in researches on terpenoids and have contributed to the structural elucidation of a number of them. It was during these investigations, he discovered new skeletal types in Sesqui- and diterpenoids. Based on his researches, he proposed two rules; the Absolute Stereochemistry Biogenetic Rule and that exotic biological materials tend to produce exotic secondary metabolites. He focused a part of his research on lac, turpentine, Cedrus deodara (Devadaaru) and Indian medicinal plants such as Guggulu Commiphora wightii, the last of which has resulted in the development of Guggulsterone, a steroid claimed to have cholesterol-lowering and nutrient properties. His researches have earned him 55 patents and the body of his work has been documented in over 290 scientific articles. he has published 10 books, including Prime Ayurvedic Plant Drugs, a 2006 publication which explores the ancient and modern traditions of Ayurveda. He has also mentored 92 research scholars, which included many notable scientists.
