During the past 2 decades, numerous articles from Europe, Asia, and more recently North America have demonstrated the capability of surgeons, emergency medicine physicians, and other practitioners to perform sonographic examinations for trauma with a high degree of skill and accuracy.1- 26,28 Rozycki et al15,16 have demonstrated that attending trauma surgeons, trauma fellows (PGY-6 and PGY-7), and senior surgical residents are capable of performing trauma sonography with sensitivity and specificity comparable with the experience of German and Japanese surgeons. Rozycki et al advocated a training program that consisted of 8-hour training sessions that were held in conjunction with resident rotations on the trauma service. The content of the course of instruction advocated by Rozycki et al included didactic, observation, and practice sessions. Rozycki et al noted the variability of the learning curve for different individuals and suggested that the skill of surgeon sonographers was well developed by the time a surgeon had performed 200 studies.15,16 Rothlin et al7 documented the implementation of surgeon-performed trauma sonography in a German center. In this experience, a single surgeon sonographer with extensive experience initially performed all studies. Gradually, additional surgeons were trained in the clinical setting by the initial surgeon sonographer. Before neophyte sonographers were permitted to perform independent ultrasound examinations, they were required to have performed 100 to 200 proctored examinations. Furthermore, this group indicated that sonographer skill continued to improve until 400 examinations were performed. Rothlin et al7 reported a slightly higher sensitivity and specificity for the most experienced sonographer compared with the "beginners," although this improvement did not appear to achieve statistical significance. Hoffman et al3 reported excellent sensitivity, specificity, and accuracy for surgeon-performed sonography in Germany, where sonographic training is mandatory for surgical residents. They stated that attending an ultrasound course and the routine performance of ultrasound studies in the emergency department under the supervision of an experienced sonographer for a few weeks will enable junior residents to determine the presence of free fluid in the abdomen.3 Ma et al18,24 described the rapidity with which emergency physicians and residents learned basic sonographic skills. They described a training program that included a 10-hour introductory course including didactic session, review of videotaped trauma ultrasound examinations, and practice sessions. Emergency physicians participating in this study were then required to perform 15 to 20 sonographic studies on normal patients before using this technique in the trauma setting. Ma et al suggested that the learning curve for new sonographers plateaued at around 50 examinations.18,24 Other studies have suggested that less extensive introductory programs are required. Tso et al6 described a course of instruction that consisted of 2 hours of didactic and hands-on training. Kern et al14 reported that senior surgical residents who attended an introductory course of 11.5 hours that included 10 practice examinations on patients with positive findings produced sensitivity, specificity, and accuracy comparable with those in other studies in the literature. Thomas et al21 documented the de novo establishment of a surgeon-performed trauma ultrasound program in a level I trauma center. In this center, trauma surgeons and fellows attended an 8-hour introductory course and were subsequently credentialed through the Department of Surgery. Thomas et al reported that sensitivity, specificity, and accuracy improved after each sonographer had successfully performed 100 studies. They concluded that surgeons achieved competency in trauma sonography rapidly and that sonography significantly reduced the cost of examination of trauma patients.21 More recently, Buzzas et al26 compared trauma ultrasound studies performed by surgery residents, trained in basic sonographic techniques, with studies performed by certified ultrasound technologists and radiologists. They found no significant differences in the sensitivity, specificity, and accuracy of ultrasound examinations performed by surgeons or radiologists. Buzzas et al concluded that a concise introductory course in trauma sonography was adequate to prepare new surgeon sonographers to perform this study independently.26 A consistent component of successful trauma sonography programs is the involvement of a core of instructors with substantial experience in sonographic skills and instrumentation. The focused ultrasound examination for trauma is not difficult to learn, but neither does it fall into the category of "see one, do one, teach one." At the present time, the credential offered by the American Registry of Diagnostic Medical Sonographers for abdominal sonography aids in giving surgeon sonographers credibility to serve as teachers of this technique.