Clinical practice guidelines can be used to help develop measures of quality of cancer care. This article describes the use of a Cancer Care Quality Measurement System (CCQMS) to monitor these measures for colorectal cancer in the Veterans Health Administration (VHA). The CCQMS assessed practice guideline concordance primarily based on colon (14 indicators) and rectal (11 indicators) cancer care guidelines of the NCCN. Indicators were developed with input from VHA stakeholders with the goal of examining the continuum of diagnosis, neoadjuvant therapy, surgery, adjuvant therapy, and survivorship surveillance and/or end-of-life care. In addition, 9 measures of timeliness of cancer care were developed. The measures/indicators formed the basis of a computerized data abstraction tool that produced reports on quality of care in real-time as data were entered. The tool was developed for a 28-facility learning collaborative, the Colorectal Cancer Care Collaborative (C4), aimed at improving colorectal cancer (CRC) care quality. Data on 1373 incident stage I-IV CRC cases were entered over approximately 18 months and were used to target and monitor quality improvement activities. The primary opportunity for improvement involved surveillance colonoscopy and services in patients after curative-intent treatment. NCCN Clinical Practice Guidelines in Oncology were successfully used to develop a measurement system for a VHA research-operations quality improvement partnership.