A cardiothoracic surgeon with more than two decades of postgraduate experience, Mohammad Salim Ratnani received his medical degree from McGill University in Montreal. He completed residencies there before accepting a fellowship at The Cleveland Clinic Foundation in Ohio, where he also became a clinical associate in training. Subsequently, Dr. Muhammad Salim Ratnani served as a clinical associate professor at West Virginia University's School of Medicine.

Throughout the following years, he became involved in teaching and research at Marshall University Graduate College and provided surgical services with groups such as Thoracic & Cardiovascular Associates, Inc., and the Charleston Area Medical Center. In 2006, he launched his own private practice known as Professional Cardiothoracic Surgery, PLLC., which he headed until he relocated to Pakistan.

As a consultant cardiac surgeon in Pakistan, Dr. Mohammad Salim Ratnani has contributed his experience to the College of Physicians and Surgeons of Pakistan and to the National Institute of Cardiovascular Diseases. He directed the latter's residency training program and spearheaded renovation of its ICU and operating rooms, and also introduced new surgical techniques.