Dr Selva-Nayagam undertook his medical studies through the University of Adelaide, graduating in 1983. Thereafter he did physician training at the Royal Adelaide Hospital, and also a period overseas at the Royal London hospital. He obtained his fellowship of the Royal Australasian college of physicians in 1992. He was then appointed as a consultant physician to the Royal Darwin hospital (1993 to 2005) with responsibilities in the areas of internal medicine, medical oncology, and Haematology. During this period he developed cancer services to the top end of the Northern Territory, including the pioneering use of tele-oncology to enhance patient care.

Dr Selva-Nayagam works in all areas of medical oncology, with a particular interest in Breast cancer, Gynae-oncology, lung cancer, sarcoma, and lymphoma. He consults at the rooms in Kimberley house, Calvary North Adelaide and St Andrew’s Medical Centre, with admitting rights to Calvary North Adelaide, Calvary Wakefield, St Andrews and Burnside hospitals.

He is the director of medical oncology at the Royal Adelaide hospital, a post he has held since 2007. He is a member of various professional bodies, including ASCO (American Society of Clinical Oncology), MOGA (Medical oncology group Australia), COSA (Clinical Oncological Society Australia), and IMSANZ (Internal medicine society of Australia and NewZealand). He is trained as a communication workshop facilitator.