Breast carcinoma metastasize more frequently to the bone, liver lung and brain as compared to other anatomical sites. As such, advanced breast tumours with secondaries involving the rarer sites often pose when a therapeutic challenge for the clinician to find a good balance between offering the most effective therapy and its potential toxicity. We report the first case of tongue metastasis from breast cancer that was successfully treated with interstitial brachytherapy, resulting in good local control and no severe side effects.