BACKGROUND Despite rigorous manual counting protocols and the classification of retained surgical items (RSIs) as potential "never events," RSIs continue to occur in approximately 1 per 1,000 to 18,000 operations. This study's goals were to evaluate the incorporation of a radiofrequency detection system (RFDS) into existing laparotomy sponge- and Raytec-counting protocols for the detection of RSIs and define associated risk factors. STUDY DESIGN All patients undergoing surgery at the University of North Carolina Hospitals from September 2009 to August 2010 were enrolled consecutively. The performance of an RFDS-incorporated accounting protocol for detecting RSIs was prospectively evaluated. Several operative metrics were recorded to identify risk factors for miscounts. RESULTS A total of 2,285 patients were enrolled. One near miss was detected by the RFDS. Thirty-five miscounts occurred, for a rate of 1.53%. The ultimate locations of miscounted items were surgical site (n = 11), within operative suite (n = 10), surgical drapes (n = 2), and emergency protocol deviations (n = 12). Perioperative variables associated with miscounts were higher estimated volume of blood lost, longer operations, higher number of laparotomy sponges used, open surgical approach, "after hours" operations, change of surgical team during operation, weekend or holiday operations, unanticipated changes in operative plan during surgery, and emergency operations. Body mass index was not associated with miscounts. Surveys completed by participating surgical staff suggested high confidence in the RFDS for prevention of RSIs. CONCLUSIONS The incorporation of the RFDS assisted in the resolution of a near-miss event (1 of 2,285) not detected by manual counting protocols and assisted in the resolution of 35 surgical-sponge miscounts. No known RSIs occurred during the study period. Risk factors for miscounts were identified and can help identify at-risk surgical populations.