 Between June 1950 and August 1959, he worked as a Civil Assistant Surgeon in various government hospitals throughout South India including Coimbatore, Cochin and Trivandrum as well as a brief stint in Minicoy Island.Warrier then moved to London to attain his Fellowship of the Royal College of Surgeons.After receiving the Fellowship in January 1960, he went on to receive training in cardiothoracic surgery in Stoke-on-Trent and Queen Elizabeth Hospital, Birmingham until 1962.