BACKGROUND: Paragonimiasis infestation is endemic mostly to Asia, Africa and South and Central America and commonly found in the lung. It is extremely rare in soft tissue. CASE: A case of paragonimiasis occurred in a 66-year-old woman who presented with a left, painful, 2-cm-diameter breast mass and had a history of eating uncooked freshwater crabs. On mammography, an ill-defined, round, isodense mass was detected without calcification. Hemorrhagic material was aspirated by fine needle aspiration (FNA) of the breast mass, which contained many parasitic eggs. They were about 90 μm long, ovoid, yellowish brown, transparent and thick shelled, with a flattened operculum at 1 end. The breast mass was completely excised. Many collapsed eggs of Paragonimus infiltrated the lobules and fibroadipose tissue, with accompanying abscess formation. To confirm the diagnosis, serologic testing for paragonimiasis was performed; it was positive for Paragonimus antibody. CONCLUSION: Paragonimiasis very rarely presents as a breast mass and can be diagnosed by FNA.