The role of the resection of primary tumour in stage IV breast cancer is unclear. Systemic therapy is recommended to prolong the survival and improve the quality of life (QOL). However, even if the systemic therapy is effective to control distant metastasis, sometimes the local lesion worsens, especially in the aggressive subtypes such as HER2-positive breast cancer. In uncontrollable tumours, the wound bed can bleed, weep and get infected, leading to dismal QOL. Our study describes two cases of patients with HER2-positive stage IV breast cancer who underwent palliative mastectomy which resulted in improvement of QOL. Local tumour control through palliative mastectomy can be beneficial for symptomatic aggressive patients with HER2-positive breast cancer to improve their QOL.