A bilateral angiographic study of the upper limbs was carried out under general anaesthesia in a group of 81 subjects--mostly (91.3%) miners--using vibrating tools. The patients' age ranged from 30 to 57 years; the time they worked as vibrating tool operators varied from 5 to 36 years; the duration of symptoms ranged from 3 months to 10 years. The mean values were 46.1, 20.9 and 3.7 years, respectively. Seventy-four subjects (91.3%) complained of Raynaud's-like phenomenon, which in 36 (44.4%) of them was elicited too, although partially, by provocative tests (cold exposure). Angiography was carried out under general anaesthesia maintained with halothane. Bilateral angiograms were available in 61 instances; in the remainder, only either right or left angiograms could be obtained. In all the subjects examined arteriographic lesions were found, mainly represented by organic stenoses and occlusions. The prevalance of such lesions was minimal at the level of the forearm arteries, and maximal at the level of the digital arteries. The 2nd finger, bilaterally, was the most frequently involved; the index finger on either side and the middle one on the right side were the most involved as to severity and extent of lesions. The 1st finger, however, was quite frequently involved too. No definite relationship between prevalance, severity and extent of arterial lesions, on one hand, and some history, clinical and functional parameters (such as age, vibrating tool usage time, smoking habit, hand arterial pattern, pulmonary silicosis, instrumental findings and Raynaud's-like phenomenon), on the other hand, could be established. As to Raynaud's-like phenomenon, it is hypothesized that such a finding could be, at least in part of cases, subsequent to the previous development of organic lesions in the digital arteries.