The possible benefits of ultrasonic cardiac output monitoring (USCOM) in emergency medicine practice could be significant if evaluated in a goal-directed protocol. The aim of this study was to perform a feasibility study in a physician-staffed prehospital emergency medicine system. This study enrolled a convenient sample of 50 patients with circulatory distress. Main criteria were visualization of acceptable curves and obtaining interpretable values. Acceptable curves and interpretable values (main criterion) were obtained for 35 patients (70%). In case of failure, the patient was very often dyspneic (80 vs. 23%, when the technique was successful, P<0.001). Mean duration of USCOM examination was 105 ± 60 s. The acceptable success rate for a new technique we observed and the high easy-to-use score suggests that the use of USCOM is feasible in prehospital emergency medicine.