The interest sparked by "medical error" can be seen in the medical literature on the PubMed search engine. In a search of entries under this heading conducted on July 12, 2022, 156,899 references are found, of which 63,322 correspond to the last ten years and 5760 to reviews. Of them, 1880, 788, and 87 are publications in Spanish, respectively.In 1999, the World Health Organization (WHO) and the Institute of Medicine's (IOM) Committee on Quality of Health Care in America published landmark reports which, using data from the states of Colorado, Utah, and New York, estimated that nearly 100,000 patients died each year from problems arising from medical errors 1,2 . Extrapolating the results of these reports to North American health-care databases, it can be concluded that around 3% (2.9%-3.7%) of hospitalizations would have experienced adverse side effects secondary to medical errors made during the hospitalization and that between 6.6% and 13.6% of these errors would have had a fatal outcome. The reports stated that one of every two incidents could have been avoided. At that time, these provocative reports generated a great deal of debate, both in public opinion and in the medical field.If we perform the theoretical exercise of transferring these results to Spain's Basic Minimum Data Set (CMBD, for its initials in Spanish) (a registry of specialized healthcare activity from the Ministry of Health), in 1999, there would have been no < 50,000 avoidable adverse events due to medical error among hospitalized patients in our country, of which between 4000 and 5000 would have been fatal 3 .Based on these data, it is not too bold to claim that medical error is among the main causes of death in Western societies, causing a similar number or even more deaths than traffic accidents or breast cancer, and many more than due to acquired immunodeficiency syndrome.Later analyses -which included new works based on different methods that attempted to update the data reported by the IOM in 1999 as they considered them limited and out-of-date-considerably increased the number of medical errors. These analyses asserted that medical error is the third leading cause of death in the United States of America (USA), behind only cardiovascular diseases and cancer, and that they account for more than seven times the number of fatalities due to traffic accidents or firearms 4,5 . Classen et al. describe a medical error rate of 1.13% which, applied to Medicare data from the period from 2013 to 2015, would entail more than 400,000 deaths per year in the USA. This is four times higher than the estimate made by the IOM in 1999 6 .The fact that medical error is very likely underestimated makes this even more worrying. On the one hand, medical errors, whether they lead to the patient's death or not, are not classified as such in the International Classification of Diseases 9 th or 10 th edition (ICD-9, ICD-10). Therefore,