Introduction: To stimulate early recognition and treatment of malnutrition, the Dutch Healthcare Inspectorate obliged all hospitals from 2008–2019 to report the number of malnourished patients with an adequate protein intake on the fourth day of hospital admission. In this article we present results over the past 11 years and discuss success factors and barriers for adequate treatment of malnourished patients in hospitals. Methods: The annual reports of hospitals on the numbers of patients with a screening result ‘malnourished’ and an adequate protein intake on the fourth day of admission were analysed. Hospitals were categorized based on the percentage of malnourished patients with an adequate protein intake on the fourth day of admission as ‘poor’ (<40% of patients in a hospital achieve an adequate protein intake), ‘moderate’ 40–60% of patients in a hospital achieve an adequate protein intake), and ‘good’ (>60% of patients in a hospital achieve an adequate protein intake). To identify success factors and barriers for adequate treatment and registration of malnourished patients in hospitals, three focus groups were held in June and July 2020. Participants were dietitians and quality employees or nurses who were involved in data collection for malnutrition indicators in their hospitals. Results: Between 2008–2019, data were reported of 339,720 malnourished patients. The relative number of patients with adequate intake of protein on the fourth day in hospital ranges from 44%-53% between 2011 and 2019. Before 2013, the number of hospitals that reported data was too small to draw conclusions about results of treatment of malnutrition. Data from 2013 to 2019, show a decline in the number of hospitals with a ‘poor’ score. The number of hospitals with a moderate score increased between 2015 and 2019 and the number of hospitals with a good score remained more or less stable, except for 2018 where more hospitals reached a ‘good’ score. Sixteen professionals from ten different hospitals participated in the focus ...