Quantitative television microscopy of nailfold capillaries of the fingers was performed in 12 patients with cutaneous lupus erythematosus (six with discoid type and six with disseminated type), in six patients with localized scleroderma (two with circumscribed type, two with linear types, and two with atrophic type), in 10 patients with systemic lupus erythematosus, and in eight patients with systemic scleroderma. The following features were analyzed and compared with a control group (n=15) of similar age: venous plexus visibility; density of capillaries; avascular fields; hemorrhages; giant capillaries; diameters of the transitional segment, the arterial, and the venous limbs; loop width; and flow stop caused by local cooling test. The patient groups with cutaneous lesions only showed no essential differences as compared with the controls. Patients with systemic scleroderma differed in almost every finding from the controls and from patients with localized scleroderma. Patients with systemic lupus erythematosus exhibited significant differences in several findings as compared with the controls and the cutaneous lupus erythematosus group, but there was overlap.