Background and aim Finding patients at nutrition risk and securing sufficient nutritional intake, is vital to decrease risk of adverse outcomes and all-cause mortality. The aims of this study were therefore to investigate the prevalence of patients being screened for nutrition risk, to determine nutritional coverage in at-risk patients and assess the prevalence of readmissions and mortality within 30 days. Methods A one-day cross-sectional study was performed at Herlev Hospital, Denmark in June 2019. Patients >18 y and hospitalized for ≥4 days were enrolled. Exclusion criteria were admission to the intensive, palliative, acute medical or maternal ward. If a patient was not screened by the ward a clinical dietitian screened the patient. Patients found to be at nutrition-risk underwent a 24-h dietary recall to assess energy and protein intake. Data on length of stay, readmissions, and mortality within 30 days were collected from the hospital patient register. Results In total 197 (F:52%) patients were included. Median (IQR) age 74y (65–81). At the audit day n = 76 (39%) had a primary screening, and n = 42 (21%) were screened within 24 h. A NRS-2002-score ≥ 3 was found in 111 patients (63%). At-risk patients were more likely to be readmitted within 30 days (45% vs. 27%, p = 0.024) and had a higher mortality within 30 days after discharge (23% vs. 10%., p = 0.0285). In patients at nutrition risk 23% covered ≥75% of their energy- and protein requirement the last 24 h. More patients covered their energy- and protein-need if they were supplemented with enteral and/or parenteral nutrition fully or partly (63% vs. 15%, p < 0.001 or had been in contact with a clinical dietitian during the admission (33% vs. 15%, p = 0.0337. There were no differences in prevalence of readmissions and mortality between those patients at nutrition risk, who covered their energy and protein need and those who did not. Conclusions The results demonstrate that the current nutritional care process is inadequate and may have serious consequences for hospitalized patients. Further effort is needed on the awareness of screening patients and how to fulfil their requirements during hospitalization.