We reviewed the sonographic findings of 42 benign papillary lesions of the breast and correlated them with pathologic findings. Sonography detected 95% of papillomas (22 intraluminal masses, four extraductal masses, nine purely solid masses, and five mixed type masses). The sonographic margins of the mass were well defined in 20 lesions and poorly defined in 14 lesions. Poorly defined margins on sonography were frequent in papillomas with pathologic pseudoinvasion and in juvenile papillomatosis. Most benign papillary lesions of the breast have the sonographic findings suggestive of intraductal origin. The sonographic findings of papillary lesions correlated well with pathologic findings.