BACKGROUND AND OBJECTIVES: Hospitalists increasingly serve as the primary physicians for children hospitalized with infections. Consequently, hospitalists frequently interact with institutional antimicrobial stewardship programs (ASPs). Understanding how these services interact can inform ongoing practice improvement efforts. The objectives of this study were to identify factors associated with ASP recommendations among hospitalist-managed children, and to determine the association of ASP interventions with clinical outcomes for hospitalist-managed patients. METHODS: We retrospectively analyzed ASP reviews of hospitalist patients from a children's hospital from March 2008 to June 2013. Clinical factors associated with an ASP recommendation were determined. Length of stay and 30-day readmission were compared between cases of agreement and disagreement with ASP recommendations. RESULTS: The ASP reviewed 2163 hospitalist patients, resulting in 350 recommendations (16.2% of reviews). Hospitalists agreed with ASP recommendations in 86.9% of cases. The odds of an ASP recommendation decreased during the study period. Ceftriaxone was the most common antibiotic associated with a recommendation (154/350, 44.0%); community-acquired pneumonia was the most common diagnosis (105/350, 30.0%). Antibiotic discontinuation was the most often recommendation; hospitalists most often disagreed with consulting infectious diseases. Disagreement with ASP recommendations was associated with a decreased length of stay of 15.4 (95% confidence interval -33.2 to 1.1) hours but not 30-day readmission prevalence. CONCLUSIONS: Pediatric hospitalists and ASPs can form an effective collaboration that improves antibiotic use while providing safe care. Better characterization of the areas of disagreement between hospitalists and ASPs is needed. Future studies are needed to identify ASP strategies that will be beneficial in other hospitalist settings.