Professor Mehta was appointed as a Consultant Haematologist to the Royal Free Hospital in November 1986. He retired from the NHS in January 2019. He was the Director of the Myeloma Service at the Royal Free Hospital. He was also the Clinical Director of the Royal Free Lysosomal Storage Disorders Unit and is Professor in Haematology at UCL School of Medicine. He is a senior examiner in Haematology at the Royal College of Pathologists. He was in charge of the diagnostic laboratory from 1986-2001; and the transfusion laboratory from 1986-1997.
His interests are clinical and laboratory haematology and metabolic medicine. His clinical interests span both malignant and non-malignant haematology and include the treatment of acute and chronic leukaemias and myeloma. He has published more than 250 peer reviewed articles in research journals, 40 chapters and three books.
He has been undertaking medico-legal work for over 15 years, providing reports for Claimants and Defendants in addition to commissioned work and court appearances.