Fine needle aspiration cytologic findings in 14 cases of gynecomastia are described. General cytomorphologic features resemble those of fibrocystic disease in women than those of fibroadenoma. Among the cytologic parameters, three-dimensional structure of epithelial cell clusters, presence of micronucleoli and irregularities of nuclear size and shape are suggestive of epithelial proliferative activity. In audition, 4 cases are proliferative breast disease without atypia and 10 cases are nonproliferative breast disease depending on cytologic criteria grading system.