Antinuclear antibody and in vivo capillary patterns were studied in 33 patients with Raynaud's phenomenon only and in 68 patients with scleroderma spectrum disorders; the results were correlated with clinical and laboratory findings. In addition, antinuclear antibody results in the groups with Raynaud's phenomenon only and scleroderma spectrum disorders were compared with those found in 70 patients with systemic lupus erythematosus (SLE). Distinct antinuclear antibody profiles were observed in the three diagnostic groups. Comparison of patients with anticentromere antibodies with others in the group with scleroderma spectrum disorders demonstrated that anticentromere antibody-positive patients tended to have a milder disease: less skin and visceral involvement, less frequent presence of hypertension, anemia, and elevated sedimentation rate. These differences did not, however, reach statistical significance. Comparison of patients with scleroderma spectrum disorders according to in vivo capillary patterns revealed that those with an "active" pattern had significantly more extensive skin involvement than those with a "slow" pattern. Visceral involvement tended to be greater in all organ systems in the group with an "active" pattern and reached statistical significance for muscle and kidney. Hypertension was also significantly more frequent in the group with an "active" pattern than in the group with a "slow" one. The latter was positively correlated with the presence of anticentromere antibody.