Spontaneous Infarction of fibroadenoma of the breast is very uncommon and may lead to difficulties in clinical and pathological diagnosis. Most reported cases occured in young women during pregnancy or lactation. This report describes imprint cytologic features of an infarcted fibroadenoma in a 19-year-old young woman without evidence of pregnancy. The smears revealed many individually scattered degenerated or necrotic epithelial or spindle stromal cells and naked nuclei on dirty necrotic background. A few sheets of cohesive uniform epithelial cells and a few fragments of stromal cells were also present. Most of the epithelial cells had pyknotic and hyperchromatic nuclei, however, cellular atypism such as pleomorphism, prominent nucleoli or mitosis were not present. Though the necrotic ductular and glandular outline of this case may bear a superficial resemblance to adenocarcinoma, obvious cytologic atypia or mitosis, even in the necrotic areas, were not present.