The aim of this study was to determine and discuss with the nursing staff their knowledge about what represents a medication error, the need to notify such an error and what would be necessary to put in these notifications. This is a descriptive quantitative study, carried out in a hospital, of which 72 professionals took part. Regarding the definition of medication errors, we found that 49 (68%) share the concept adopted in this study. Regarding the need of notification, 67 (93%) declared that there is such a need. As regards the content of the notification, 63 (85%) had a similar concept to the one used in this study. The need to further approach aspects related to medication errors was evident.