Breast reduction is a common surgical procedure performed by plastic and oncoplastic breast surgeons. The authors report on the incidence and management of cancer and atypical hyperplasia in breast reduction specimens from one institution over a 10-year period. All patients who underwent breast reduction surgery at Northern General Hospital, Sheffield were identified from an electronic prospective database. The histopathology reports were analyzed. Case records of all patients with significant abnormalities were retrieved and examined to identify their management and follow-up. Between October 1999 and April 2010, 1,588 patients underwent breast reduction. Nine specimens showed atypical hyperplasia (0.57%). Five cancers were detected (0.31%). Four of the five patients had normal screening mammograms 1-3 years before the reduction operation. Of these cancers, four were invasive (three lobular, one ductal) (0.25%) and one was DCIS (0.06%). A lump was felt macroscopically by the pathologist in two of the four patients with invasive cancer. The patients with DCIS did not undergo further surgery, whereas those with invasive disease underwent mastectomy (three patients) and axillary nodal staging (four patients). None of the patients with normal post-reduction breast imaging had residual cancer on histology. The incidence of occult carcinoma in breast reduction specimens is low. Patients should be counseled with regards to the possible consequences preoperatively.