Aim: Aim of this study is to report two cases of generalised vitiligo (GV) who developed cancer (CA) breast. Case Report: First case is one of CA right breast with history of GV since three years treated with right modified radical mastectomy. Other one is also a case of CA right breast with history of GV since two years treated with neoadjuvant chemotherapy and radiotherapy and followed by right modified radical mastectomy. The second patient developed fresh area of depigmentation at the site of radiotherapy. Discussion: Even though the association of autoimmune disease (AD) and cancer is well known, there are not much of reports in the literature. The association might be incidental/coincidental or cause and effect relationship. The association might also be cancer (CA) developing in a patient of AD or development of AD in a cancer patient during or after treatment. AD may increase the risk of developing CA or reduce the risk. AD may worsen pre-existing CA or may be a sign of CA regression. Both our cases were known patients of GV who developed CA breast. One of them had developed fresh area of vitiligo after radiotherapy in the post mastectomy site. Conclusion: Association between AD and CA is well known for a long time. But many aspects of this association with reference to incidence, exact type of association or background of such association whether genetic, environmental or post therapeutic are still not well understood. Our case reports may incite and add up for further studies on these issues..