Aims: To assess and compare the rates of malnutrition in Hammersmith Hospital NHS Trust over a 5-year period following changes in hospital nutrition care strategies. Methods: Design: Three consecutive cross-sectional studies carried out in 1998, 2000 and 2003. Setting: Inpatients at Hammersmith Hospital NHS Trust. Participants: A total of 2283 inpatients aged over 16 years old, 686 in 1998, 780 in 2000, 817 in 2003. Inpatients excluded: ventilated patients, ante/post-natal women and people aged < 16. Interventions: Improvements in the catering service and nutrition education provision in 2000, and the implementation of a nutrition screening too[ and 'Better Hospital Food' in 2003. Main outcome measure: Prevalence of malnutrition. Results: There was a reduction in the prevalence of malnutrition in 2000 and 2003 from baseline data in 1998 (1998: 23.5%, 161/686; 2000: 20.4%, 159/780; 2003: 19.1%, 156/817; P < 0.001). The odds ratio of being either at risk of malnutrition or malnourished was reduced in both 2000 and 2003 by approximately 33% (P = 0.001). Indicators of good nutritional practice also improved: Weighing patients on admission increased from 37.5% (257/686) in 1998, to 42.9% (335/780) in 2000, and 59.6% (487/817) in 2003 (P < 0.001). Dietetic referrals also increased from 31.5% (216/686) in 1998 to 41.6% (340/817) in 2003 (P < 0.001)(no change in 2000, 31%, 242/780). Appropriate referrals also improved, results showing that the proportion of malnourished patients who were referred showed a dramatic increase in 2003 (1998: 91/161, 56.5%; 2000: 85/159, 53.5%; 2003: 111/156, 71.2%; P = 0.003). Conclusions: The prevalence of malnutrition in hospital can be influenced by the implementation of a variety of nutrition care strategies, which target identification of malnutrition and its treatment. (c) 2005 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.