Vascular signals arising from pleura-based lung lesions were studied in 50 patients using pulsed Doppler ultrasonography. Twenty-seven had malignant lesions and 23 benign lesions. In 24/27 of the malignant masses, we observed no Doppler signals: in 2 cases, a low-velocity, turbulent, pulsatile flow was demonstrated; in 1 case pulsed Doppler ultrasonography showed only a low-velocity, continuous flow. In 20/23 of the benign lesions, we found 2 types of Doppler signal waveforms: an irregularly pulsatile, venous-like signal, and a regularly pulsatile, arterial-like waveform. The last 8 patients of our series underwent color Doppler ultrasound examination, which demonstrated the presence of arterial and venous vessels in 4 benign lesions and the absence of blood flow in 4 malignant masses. To our knowledge, we report for the first time the ability of obtaining Doppler signals from a variety of lung lesions. The actual clinical relevance of this application requires further studies.