We present a case of an XX male with carcinoma of the breast and primary infertility. He was admitted to hospital with recurrent chest pains, but a history of surgery for breast carcinoma, gynaecomastia and the finding of bilaterally atrophied testes, coupled with the fact that he had never fathered children, necessitated further investigations. Chromosomal analysis showed a 46, XX male genotype with a normal X chromosome and an abnormal X chromosome formed by translocation between the short arm of one X chromosome and the Y chromosome. By using fluorescence in situ hybridisation, the patient proved to be SRY positive, the sex-determining region of the Y chromosome. In this rare genetic abnormality, males retain normal phenotype but they are generally of short stature, have gynaecomastia, and may have genital anomalies. They are infertile and at increased risk of developing carcinoma of the breast. This seems to be the first documented case of carcinoma of the breast in an SRY positive XX male. This particular case illustrates the need for all cases of male breast cancer to undergo full endocrinological assessment, especially in the presence of genital anomaly or infertility.