Juvenile papillomatosis of the breast is a benign, localized proliferative condition encountered mainly in young women. We describe the contrast-enhanced MR imaging findings, including dynamic data, of a patient with histologically proven juvenile papillomatosis of the breast. The pre-contrast T1 weighted sequence showed a hypointense lobulated mass which enhanced markedly in the post-contrast images. In the dynamic sequence the lesion showed a benign enhancement profile. The most specific feature was the presence of multiple small internal cysts, best shown on the T2 weighted images. This constellation of findings should suggest juvenile papillomatosis.