Objective: to analyze the relationship between knowledge and the adequacy of nursing annotations and their determinants. Method: An exploratory, descriptive and quantitative approach, carried out in the Medical Clinic and in the Adult Intensive Care Unit of a Brazilian university hospital. A total of 114 professionals and 41 medical records were included. Results: The professionals had a high mean score of knowledge and a low mean score of adequacy and there was no correlation between them (rs = -0,122; p > 0.05). The knowledge score was higher for professionals graduated in Nursing. The mean score of adequacy was higher for the professional category nurse if packed in Medical Clinic and with the professional that was dissatisfied with the training. Conclusion: there is no relationship between the professional's knowledge about nursing notes and the adequacy of the notes, which leads to serious ethical, legal and patient safety issues.Descritores: Anormalidades congênitas; Recém-nascidos; Mortalidade infantil; Enfermagem neonatal.