Youth with autism spectrum disorder (ASD) are psychiatrically hospitalized at high rates. Though specialized psychiatric units are effective, few specialized units exist. The ASD Care Pathway (ASD-CP) was developed as a scalable approach to improving care in general psychiatric units through staff training and a package of autism-specific intervention strategies. An evaluation of the effectiveness of the ASD-CP in a public hospital child psychiatric service compared 18 months (n = 17) versus 18 months (n = 20) post implementation. Average length of hospital stay decreased 40% (22.4–13.4 days) and use of crisis interventions decreased 77% (holds/restraints; 0.65/day to 0.15/day), though each result only approached statistical significance (p = 0.07; 0.057). This study provides preliminary evidence for improved outcomes after implementation of an ASD-CP.