© AANS, 2017. OBJECTIVE: Many neurosurgical training programs have moved from a 24-hour resident call system to a night float system, but the impact on outcomes is unclear. Here, the authors compare length of stay (LOS) for neurosurgical patients admitted before and after initiation of a night float system at a tertiary care training hospital. METHODS: The neurosurgical residency at the University of Alabama at Birmingham transitioned from 24-hour call to a night float resident coverage system in July 2013. In this cohort study, all patients admitted to the neurosurgical service for 1 year before and 1 year after this transition were compared with respect to hospital and ICU LOSs, adjusted for potential confounders. RESULTS: A total of 4619 patients were included. In the initial bivariate analysis, night float was associated with increased ICU LOS (p = 0.032) and no change in overall LOS (p = 0.65). However, coincident with the transition to a night float system was an increased frequency of resident service transitions, which were highly associated with hospital LOS (p < 0.01) and ICU LOS (p < 0.01). After adjusting for resident service transitions, initiation of the night float system was associated with decreased hospital LOS (p = 0.047) and no change in ICU LOS (p = 0.35). CONCLUSIONS: This study suggests that a dedicated night float resident may improve night-to-night continuity of care and decrease hospital LOS, but caution must be exercised when initiation of night float results in increased resident service transitions.