Paediatric drug therapy is a challenge for nurses as the physiological differences between children and adults greatly influence the degree of efficacy of a drug. Worldwide, different studies have reported that there are errors in the administration of intravenous drugs. Fortunately, the cases in which the medication error is of vital importance to maintain the safety of the patient and the nurse are exceptional. In Mexico, no published reports on this subject were found, as there is no culture that favours open communication of errors that occur during care and what caused them. This is why we wanted to know what are the most frequent errors made by nursing staff related to the administration of intravenous drugs at the CMN SXXI Paediatric Hospital?