54 Background: A successful effort was led in Ontario to increase ST CPOE adoption from 73% to 92% to support safety of patients receiving complex systemic treatment. This work included implementation at 19 hospitals from 2011-2013. The implementation process included identification of multidisciplinary team champions, baseline workflow analysis and development of a future desired state. Findings from this project’s benefits evaluation are presented. Methods: Each hospital was required to collect pre and post implementation measurements for medication errors, transcription errors and order clarity/completeness. Six months post implementation, a semi-structured telephone interview was conducted with representative hospitals (9/19) to obtain qualitative feedback on how implementation impacted workflow, inter-professional practice and workload. Results: Hospitals that implemented showed: 1) decrease in overall medication error rates. 2) decrease in transcription error rates and 3) decrease in number of unclear or incomplete orders. Qualitative feedback from hospital leads indicated that the “future desired” workflow was achieved by all. Most hospital respondents indicated that clarity of inter-professional communication regarding orders improved and in most cases overall workload did not increase. Conclusions: The findings reinforce the benefit associated with implementation of ST CPOE in outpatient settings. Lessons learned in Ontario can be leveraged to support successful implementation of ST CPOE in other jurisdictions. Critical implementation success factors included: 1) leadership and multi-disciplinary involvement; 2) provision of funding and cost sharing; 3) facilitation of process improvement through established methodologies, 4) knowledge transfer and peer group led education and training sessions. [Table: see text]