He graduated with an MBBS and MS from the University of Lucknow in 1950 and 52 respectively, and then trained at the University of London and obtained his FRCS in 1956. He further obtained specialist training in neurosurgery at Oslo, Norway and Montreal, Canada. After a brief tenure as a professor at the K.G. Medical College, Lucknow (1963–65), he moved to the prestigious All India Institute of Medical Sciences, New Delhi where he founded the neurosurgery department he has been a professor of neurosurgery, a Bhatnagar Fellow (CSIR) and then a professor emeritus. Tandon, an elected fellow of the National Academy of Medical Sciences, was the President of the Indian National Science Academy in 1991-92 and has been awarded Padma Shri (1973) and Padma Bhushan (1991) by the Government of India. Tandon also serves as the president of the National Brain Research Centre Society, Manesar, Haryana, India. He is a member of the Norwegian Academy of Science and Letters.