We examined the density of tumor enhancement on intravenous digital subtraction angiography (IV-DSA) in patients with breast cancer in relation to disease-free survival. The subjects of the present study consisted of 103 patients with invasive ductal carcinoma measuring 5 cm or less treated from July 1988 to September 1993. In the 103 patients, 15 had distant metastasis. The region of interest was set in the areas enhanced by IV-DSA of the breast. The maximum density (MAX) was calculated by the time-density curve. When the patients were divided according to three classes of MAX, i.e., 0-5.0 pixels (group A, n = 23), 5.1-9.0 pixels (group B, n = 50), 9.1 pixels or more (group C, n = 30), disease-free survival was highest in group A followed by group B and C, respectively. The disease-free survival rate in group C was significantly lower than that of group A or B (p < 0.05). Thus, high values of MAX were associated with low rates of disease-free survival. Since the value of MAX was found to be independent from other prognostic factors by multivariate analysis, these results indicate that MAX has a close correlation with metastasis or recurrence of breast cancer, making IV-DSA a promising prognostic factor.