The authors report on a consecutive series of 175 contralateral metachronous breast cancers. Eighty-six cases detected in women self referring for cancer-related subjective symptoms were compared to 89 cases detected as asymptomatic at routine examination. Detection in the asymptomatic phase was associated with a more favorable stage, but no differences in survival rates were observed between asymptomatic or symptomatic cancers when survival was measured from the date of first cancer diagnosis, in order to adjust for lead time bias. The nodal status of the first or of the second cancer was the only variable of prognostic value on univariate analysis, whereas a significant association to prognosis was evidenced only for nodal status of the first cancer. The study suggests that routine clinico-mammographic check-up may achieve early detection of contralateral metachronous breast cancer in the asymptomatic phase, but this does not seem to have a relevant impact on prognosis. The occurrence of a second primary breast cancer seems to be an indicator rather than a determinant of a worse prognosis.