In literature it is reported that accurate nursing documentation improves patients' outcomes but nursing planning data is seldom available. The accuracy of nursing documentation in hospitals has been assessed in many healthcare settings through the detection of three key elements of nursing decision-making: diagnoses, interventions and outcomes. However, studies conducted in Italy are scant and none of them have been conducted in Lombardy Region. the aim of this study is to assess the accuracy of nursing documentation in six hospitals. Accuracy in documentation's compilation was sought, as well as the three essential elements expected in the nursing decision-making process: diagnoses, interventions and outcomes. a multicentre retrospective observational study was conducted on a sample of 430 computerized and paper-based nursing records in surgical and medical areas. D-Catch instrument was used to evaluate documentation's accuracy. This instrument is divided into six sections, with scores ranging from one to four: a higher score corresponds to a greater accuracy of the documentation. The six sections assess whether the documentation structure and the assessment are accurate, the presence of a nursing diagnosis, the accuracy of interventions and assessments and documentation's clarity and legibility. it emerged that in the six hospitals there is a structured and personalized nursing documentation. From the 430 nursing documentations, a total of 623 nursing diagnoses were observed. Diagnoses reached an average score of 2.5, with significant differences between surgical and medical areas and between computerized and paper documentations. Interventions also showed significant differences between surgical and medical areas, and between computerized and paper documentation, with an average score of 2.04. The outcomes received the lowest scores with an average of 1.75. the specific nursing data that would make the care process evident are hardly visible and, despite the nursing records of the six hospitals being oriented by a conceptual model, there is no shared terminology that helps nurses to describe univocally the care process. The introduction of a standardized nursing language and an integrated computerized medical record could help to improve the accuracy of the documentation.