Purpose : To understand the different signal intenssities seen on contrast enhanced magnetic resonance imaging (MRI) in multiple fibroadenoma of the breast, and to compare these with color Doppler ultrasonographic (CDUS) and hishtologic findings.Materials and Methods : MRI (1.0 Tesla, T1WI, T2WI, 3D-gradient echo dynamic contrast enhancement study) findings of 24 histologically proven cases of fibroadenoma in five patients were evaluated and compared with the histologic components (myxoid, adenomatous, fibroud). In addition, vascular flow, as seen on CDUS and histologic section, was compared.Results : The observed degree of signal intensity was claddified into three groups, as follows : negative, 8.3%, mild to moderare, 54.2%;marked, 37.5%. On histologic section, the greater the fibrotic component, the higher the intensity of MRI enhancement, the greater the glandular component, and the intensity. CDUS showed vacular flow in only one tumor larger than 3cm in diameter. Vascular patterns of tumors on CDUS were dots in mass and detouring pattern, bot in this case and in strongly enhanced cases, tumor vascularity-as seen on histologic section-showed no significant increase.Conculusions : Different signal intensities seen on contrast enhanced MRI in multiple fibroadenoma of the breast may be related more to the amount of glandular and fibrotic component than to increased tumor vascularity.