Introduction Over the last decades, treatment of breast cancer has become increasingly more effective. Consequently, an increasing number of women are living with late effects of breast cancer treatment, including disfiguring scars, deformity or asymmetry of the breast, secondary lymphoedema and other physical and psychosocial late effects. Data from this study will provide knowledge on how to guide breast reconstruction in the future towards outcomes with fewer complications, higher long-term quality of life (QoL) and satisfaction with the aesthetic outcome. The development of secondary lymphoedema, for which the effect of breast reconstruction has yet to be established, will be thoroughly examined. Methods and analysis Women receiving breast reconstruction (autologous and implant based) at the Department of Plastic Surgery and Burns Treatment, Rigshospitalet, will be invited to participate. The patients will be followed for 10 years postoperatively. Demographic, health-related, oncological characteristics and treatment data will be registered. Validated assessment tools, such as the BREAST-Q and Beck Depression Inventory, will be used to measure an extensive range of clinical outcomes, including QoL, life and aesthetic satisfaction and depression. Arm range of motion will be measured with a goniometer and lymphoedema by bioimpedance spectroscopy, compared with circular arm measurements. Ethics and dissemination This study will be conducted according to the 5th version of the Helsinki Declaration. The regional ethical committee for Capital Region Denmark did not find the study notifiable, according to the law of the committee § 1, part 4. All data will be anonymised before its publication. This study will be conducted according to the Danish data protection regulation and is catalogued and approved by the Capital Region Head of Knowledge Centre. According to the Danish health law § 46, part 2, this study does not need the Danish Patient Safety Authority's approval. The findings of this study will be submitted to international peer-reviewed journals.