Aim: Synchronous occurrence multifocal tumors across multiple tissues are common and mostly metastatic and sometimes include a small number of concurrent multiple primary tumors that are not metastatic poses so it is a difficult challenge to treatment, so we present a case of synchronous primary well differentiated adenocarcinoma of bladder and invasive ductal carcinoma of breast. Case report: A 59-year-old female patient presented to urology department with the complaint of pain and hematuria. There was no relevant family history for all type of cancers. Clinical examination was normal. The patient had no history of tobacco using and any other cancer in the past. Through core needle biopsy,the patient was diagnosed with invasive ductal carcinoma of left breast.Allsentinel lymph node of breast was sent to pathology and it revealed that the node is involved.Simultaneously, partial mastectomywas donefor patient, and then axillary lymph node dissection has been done; six lymph nodes were removed and sent to the lab. Discussion: A comorbid manifestation of breast and bladder carcinomas is rare, little similar case has been published so far. Synchronous primary cancers have rarely been reported, but it is believed that the incidence is rising. Prevention, making an early diagnosis and the treatment of multiple cancers will become even more important in the future. Conclusion: It is important to present this case because of many literature have been reported cases of bladder metastasis of the breast, but we presents a concurrent primary breast and bladder cancer report.