Negligence by doctors has to be determined by judges who are not trained in medical science. They rely on experts' opinion and decide on the basis of basic principles of reasonableness and prudence. This brings into a lot of subjectivity into the decision and the effort is to reduce it and have certain objective criteria. This may sound simple but is tremendously difficult as medical profession evolves and experimentation helps in its evolution. Thus, there is a constant tussle between the established procedures and innovative methods. But, innovation simply for the sake of being different, without any reason is not acceptable. And, these issues make it extremely challenging to decide negligence by doctors. The paper examines the concept of negligence in medical profession in the light of interpretation of law by the Supreme Court of India and the idea of the 'reasonable man'.