This is a case of a woman in her fifth decade of life who presented with a lump in her left breast. The patient underwent extensive breast investigations which did not confirm one particular diagnosis. The lesion was excised, and histological findings confirmed the diagnosis of a giant breast hamartoma. This case is interesting due to the largeness. As well as this, giant breast hamartomas are uncommon, and this case highlights the difficulty in their diagnosis and frequent misdiagnoses, potentially contributing to their reported low incidence rates. Diagnosis is difficult due to the complex appearance of the mass on imaging, raising the possibility of malignancy. Core biopsy is unremarkable, with the final diagnosis only possible on histological examination of the resected mass.