Copyright © 2017 American Society of Clinical Oncology. All rights reserved. Introduction In 2012, ASCO created the Top Five Choosing Wisely (CW) list of low-value tests and procedures for which there is little evidence of benefit. ASCO's Quality Oncology Practice Initiative, an oncologist-led practice-based quality assessment program, includes measures on the basis of these recommendations. Methods CW test measures from spring and fall 2013, spring 2014, and spring 2015 were evaluated for concordance rates, change in the concordance over time, and variability by practice characteristics. Practice characteristics recorded included geographic location, academic affiliation, number of new cases, number of medical oncologists, and rounds of participation in Quality Oncology Practice Initiative. Medians, interquartile ranges, and percentages were calculated for concordance with recommendations and practice characteristics. Change in recommendation concordance over time was assessed using linear regression models. Results From 2013 to 2015, 341 unique oncology practices abstracted the CW measures. Performance varied for specific recommendations. The median concordance was best for measure 1 (patients with low or undocumented performance status who received chemotherapy), where concordance ranged from 78.4% to 83.3%. The lowest concordance was for measure 3 (use of biomarkers or advanced imaging tests for surveillance in early breast cancer), where concordance ranged from 67.7% to 74.2%. Performance on CW measures varied markedly by individual practice. Variability over time and by practice characteristics was observed. Conclusion Performance on ASCO's CW demonstrates room for improvement. Concordance rates varied substantially by practice. Further education on CW measures is needed to improve patient care and enhance value.