Bhajan obtained a Bachelor of Medicine & Surgery from the University of Queensland, Australia in 1986. He trained as a General Physician at the Greenslopes Hospital in Brisbane and as a Respiratory Physician at The Prince Charles Hospital in Brisbane. He became a Fellow of the Royal Australasian College of Physicians in 1995. He moved to Perth in 1996 where he trained as a Sleep Physician and completed a PhD (Distinction) in respiratory muscle physiology in 2003. He has been a recipient of the Australian Lung Foundation-Boehringer Ingelheim Chronic Airflow Limitation Fellowship and, on two occasions, the Thoracic Society of Australia & New Zealand (TSANZ) John Reid prize for physiological research. His current appointments are (1) Head of Department, Pulmonary Physiology & Sleep Medicine, Sir Charles Gairdner Hospital, (2) Clinical Professor, School of Human Sciences, University of Western Australia, and (3) Director, West Australian Sleep Disorders Research Institute. He leads a productive academic clinical sleep disorders service. He publishes widely and speaks regularly at scientific meetings on various aspects of respiratory physiology and sleep medicine.