Four hundred and thirty-eight patients with biopsy-proven benign breast disease were followed annually in a prospective manner for 4-17 years, to analyze breast cancer risk, correlations with cancer development and recurrence during follow-up. Twelve breast cancers developed in 12 patients during follow-up, giving a 2.6 fold increased cancer risk over the reference population. No association was found between patients who developed cancer and those who did not with respect to the initial histologic feature (p = 0.9), the age at entry by decades (p = 0.4) and relative to menopause (p = 0.3), the presence of cysts (p = 0.5) or calcification (p = 0.2) in the biopsy specimen, a family history of breast cancer (p = 0.7) or the follow-up time (p = 0.9). Benign breast disease does not inevitably lead to recurrence. Moreover, 47% of the 438 patients never had any recurrence and were free of symptoms during follow-up, and 84% never required a further operation. We conclude that an aggressive approach to benign breast disease is not justified, for any type of lesion as defined in this report.