Subcutaneous mastectomy (SCM) has been performed in 323 patients with invasive breast cancer or ductal carcinoma in situ (DCIS) over the last 20 years. This paper assesses the oncological safety of this operation with particular reference to local recurrences (LR) in the skin flaps. LR was assessed in the 134 patients who did not receive post-operative irradiation to the flaps and were followed up for a minimum of 30 months. The rates of LR were similar for SCM (16%) and for women who underwent simple mastectomy without post-operative irradiation (SM) for invasive cancer (14%) over the same time period, both overall and after prognostic stratification. In DCIS LR was only found in women treated with SCM. Four of the five recurrences (from 33 women) were in the nipple and later in the series patients with microscopic tumour involvement in the nipple received prophylactic irradiation to the nipple only; five patients treated in this way have not suffered LR. Subcutaneous mastectomy followed by insertion of a prosthesis is a safe alternative to mastectomy, since it carries no higher risk of LR. It is the simplest form of reconstruction in those proceeding to silicone implant and has the potential of achieving an excellent cosmetic result. Failure does not compromise the chance of more complex reconstruction procedures.