The purpose of this study was to determine the normal characteristics of the lower extremity arterial system as seen with color Doppler. A total of 420 arterial segments from the level of the proximal abdominal aorta to the distal tibial and peroneal vessels were examined with a color ultrasound scanner in 10 normal volunteers. Each arterial segment was examined for the presence of triphasic flow, wall irregularities, calcification, bruits, collaterals, and post-stenotic flow patterns. Standard duplex spectral waveform data were also obtained at each site. As expected, triphasic flow was present and detected by color Doppler in the majority of arterial segments. Color patterns suggesting the presence of bruits, collaterals, or post-stenotic flow were absent in all cases.