Background & aims: The effectiveness of combining interventions (nutrition screening, provision of oral nutritional supplements, and flagging patients for feeding assistance) in preventing nutritional decline is unknown. Methods: We conducted a stepped wedge, randomised, cluster trial to evaluate a multifaceted nutritional intervention implemented across a metropolitan hospital. Change in body weight after the first, and second, week of stay; use of the Malnutrition Universal Screening Tool (MUST); and requests for feeding assistance for patients were measured across control (n=135) and intervention (n=240) time periods. Results: In the first week, patients lost 0.4±3.3% of their body mass, equivalent to 0.4±2.3kg and a reduction in body mass index (BMI) of 0.1±0.8kg/m2. Unadjusted analysis identified some reductions in nutritional decline in the intervention group, particularly in week 2 when 14% of patients in the intervention group experienced weight loss, compared to 33% of control patients (P=0.053).In week 1, significantly more intervention patients had a completed MUST (201/238, 84.5%, P=0.000) and a feeding assistance referral (48/240, 20%, P=0.004). 'At risk' patients with BMI <20 gained 0.6±4.4% of their body mass. Multivariable analysis of week 1 data found no relationship between weight loss outcomes and the treatment, the ward or time period. Conclusions: Weight loss after one week did not differ between control and intervention wards. Implementation of a multifaceted intervention was facilitated by the study design, however, the study reinforced difficulties in accurately weighing patients in hospital. Trail register: ACTRN12611000020987.