The objectives of this study were to determine the accuracy of Emergency Physicians (EP) performing focused right upper quadrant (RUQ) ultrasound, to quantify how sonographic experience affects accuracy for gallbladder pathology, and to establish the time needed to complete a focused RUQ ultrasound. A convenience sample of patients with suspected gallbladder disease received a focused RUQ ultrasound by an EP. Sonographic findings, number of previous RUQ ultrasounds performed, and time for examination completion were recorded. Each patient then had a formal RUQ ultrasound by a sonographer blinded to the focused RUQ ultrasound results. Focused RUQ and formal ultrasound findings were compared, with the exception of the sonographic Murphy sign, which was compared to pathology reports. One hundred nine patients were enrolled. Fifty-one had gallstones. Forty-nine were detected by EPs, yielding a sensitivity of 96% [95% confidence interval (CI).87-.99]. Of the 58 patients without gallstones, 51 were correctly diagnosed by EPs (specificity = 88%, 95% CI.77-.95). The sonographic Murphy sign was present during 54 emergency examinations, but in only 24 formal studies. When compared to pathology reports, the emergency sonographic Murphy sign had a sensitivity of 75% compared to the formal ultrasound sensitivity of 45% for acute cholecystitis. EPs were less accurate for other sonographic findings, and level of experience had little effect on sensitivity or specificity for detecting gallstones. Eighty-three percent of emergency studies were completed in less than 10 min. Gallstones are accurately detected by EPs in a timely fashion. Additionally, compared to the radiologist's interpretation, the EP-detected sonographic Murphy sign was more sensitive for diagnosing acute cholecystitis.