The aim of this study was to describe the process of developing a nursing assessment tool for hospitalized adult patients with liver cirrhosis. A descriptive study was carried out in three stages. First, we conducted a literature review to develop a data collection tool on the basis of the Conceptual Model of Wanda Horta. Second, the data collection tool was assessed through an expert panel. Third, we conducted the pilot testing in hospitalized patients. Most of the comments offered by the panel members were accepted to improve the tool. The final version was in the form of a questionnaire with open-closed questions. The panel members concluded that the tool was useful for accurate nursing diagnosis. Horta's Conceptual Model assisted with the development of this data collection tool to help nurses identify accurate nursing diagnosis in hospitalized patients with liver cirrhosis. We hope that the tool can be used by all nurses in clinical practice.