A case of mucinous carcinoma of the breast is reported in a female aged 71 years. On gross examination of the left mastectomy specimen two relatively well-circumscribed masses with a gelatinous cut surface were found. Touch imprint cytology was consistent with a low-grade malignancy and histologic and histochemical examination revealed a mucinous carcinoma. Careful prospective correlation between the cytological appearances of cells in imprints and the subsequent histopathology may lead to a more precise cytodiagnosis of a tumor associated with a comparative good prognosis.