For several years and in many different ways, medical errors have been studied. As expected, the majority of efforts have been directed to prevent clinical errors during the different phases of health care. Nevertheless, less attention has been given to what happens when a negative effect has already occurred. The present work describes the doubts and difficulties that doctors deal with when facing an error and to describe the communicational tools that the literature offers to cope with them. The definition of medical error was the starting point that was used to later analyze the evidence about what, why and how to inform medical errors from an ethical and technical point of view. In the light of new legal exigencies, communicational and health protocols are revised, distinguishing those that are used for conveying bad news and medical errors. The importance of the ethical and communicational formation of the professionals is emphasized, identifying certain hindering aspects of the medical culture. This culture promotes an idea of the doctor as a professional who knows everything, does not make mistakes and acts in isolation. These do not reflect personal attributes in the professional and in the health team, required for a good professional practice.For several years and in many different ways, medical errors have been studied. As expected, the majority of efforts have been directed to prevent clinical errors during the different phases of health care. Nevertheless, less attention has been given to what happens when a negative effect has already occurred. The present work describes the doubts and difficulties that doctors deal with when facing an error and to describe the communicational tools that the literature offers to cope with them. The definition of medical error was the starting point that was used to later analyze the evidence about what, why and how to inform medical errors from an ethical and technical point of view. In the light of new legal exigencies, communicational and health protocols are revised, distinguishing those that are used for conveying bad news and medical errors. The importance of the ethical and communicational formation of the professionals is emphasized, identifying certain hindering aspects of the medical culture. This culture promotes an idea of the doctor as a professional who knows everything, does not make mistakes and acts in isolation. These do not reflect personal attributes in the professional and in the health team, required for a good professional practice.