IntroductionThe incidence of multiple primary cancers is reported to be between 0.3% and 4.3%. The second primary lesion is identified either simultaneously with the primary lesion (synchronous) or after a period of time (metachronous). Few cases of metastasis of breast carcinoma to the esophagus and vice versa have been reported in the past.Case presentationWe report an extremely rare case of a 55-year-old Indian woman who had carcinomas in both the esophagus and the breast simultaneously. She was treated successfully using combined modalities of surgery, chemotherapy and radiation therapy.ConclusionCases of synchronous double malignancies can be treated by dealing with the malignancy in the two sites as independent carcinomas. We have to take into consideration the total dose of radiation to a critical organ as well as the effect of the total dose of toxic chemotherapeutic drugs on our patient.