OBJECTIVES: Poor nutritional status is adversely associated with several functional, clinical, and economic outcomes. Malnourished patients are at risk for longer hospitalizations compared to well-nourished patients, thus increasing the likelihood for patients to experience serious safety events. We assessed the effect of the administration of a quality improvement program (QIP) integrating nutrition risk screening by nursing staff at the time of admission and oral nutrition supplementation (ONS) of hospitalized patients on length of stay as compared to pre-QIP historical controls. METHODS: Average hospital length of stay of historical controls pre-QIP was 7.2 days. The QIP patients were identified at risk for malnutrition or malnourished during their stay at one of the four participating hospitals. In all four QIP hospitals, the electronic medical record (EMR) was upgraded to include Malnutrition Screening Tool (MST) and condition-specific ONS was administered to all patients at risk for malnutrition (MST ≥ 2). In two of the QIP hospitals (namely QIP+), in addition to the initiatives in QIP, aggressive nutrition-related procedures were implemented (faster administration of ONS, specific discharge instructions, ONS coupons, and 4 follow-up/compliance telephone calls). RESULTS: Data from 1269 patients enrolled between October 2014 and April 2015, and 1319 historical controls admitted at the four QIP hospitals a year prior to QIP implementation were analyzed. The post-QIP hospital length of stay of all four QIP hospitals was 5.4 days, showing an absolute rate reduction of 1.8 days, as compared to pre-QIP length of stay of 7.2 days (25% relative risk reduction, P<0.001). Relative risk reductions for the two QIP+ versus two QIP hospitals were 26.4% and 25%, respectively (P values<0.001). CONCLUSIONS: Hospital length of stay among malnourished adult hospitalized patients can be significantly decreased through a comprehensive ONS QIP, thus enforcing the need to embed malnutrition risk screening and/or automatic nutritional interventions in routine clinical practice.