Medical research casts a great impact on health of the entire human population so it must be conducted and publicized without dishonesty or bias. Any misrepresentation can have extremely serious consequences for patients and clinical practice. Unfortunately, fraud and deceit have increasingly been detected and have become a problem in today's research. They are falsification, fabrication, plagiarism, and deliberate use of inappropriate statistical analysis. It is sometimes difficult to differentiate fraud from incompetence, errors, bias, and misunderstanding. Many fraudulent articles are still undercover. The question is how to detect and prevent the fraud and deceit in medical research. In addition, the system of handling research misconduct is still lacking. Critical audit and inspection are required to diagnose it. There is no standard guideline to treat fraud. Prevention is the best way of treatment. This relies on research institutions, editors of journals, citing authors, and, most of all the researchers who must adhere strictly to medical professionalism, which is solely based on honesty and ethics to self-regulate and conduct only ethical and genuine research.