A paraffin injection is regarded as to be a simple and effective method of breast augmentation. However, there are few reports on the long-term complication of a paraffin injected breast. The generation of breast cancer from a paraffinoma of the breast is rare, even though there is no clear evidence to suggest any relationship between a paraffin injection and breast cancer. We encountered a case of infiltrative ductal carcinoma arising from paraffinoma tissues. A 49-year-old woman had undergone bilateral breast augmentation by paraffin injection 20 years earlier. She presented with bilateral diffuse painless palpable masses with reddish discoloration and painful swelling in her left breast. She had been managed with a bilateral simple mastectomy including the mass. After discharge, the pathology report showed infiltrative ductal carcinoma of the left breast mass. The patient was readmitted for additional surgery, and she underwent a modified radical mastectomy. Ultrasonography is a useful diagnostic tool for detecting a breast mass, particularly in a dense breast. However, ultrasonography has a limitation in the case of a paraffinoma. Through this case, it is necessary to review the radiological (mammography, ultrasonography, magnetic resonance imaging, plain film) appearances and the histopathological feature to help make an accurate diagnosis and to differentiate between a carcinoma and a paraffinoma. In rare cases, a breast ductal carcinoma can be combined with a paraffinoma. Therefore, a paraffinoma must be carefully managed due to the potential risk of a carcinoma.