Gossypiboma or retained surgical sponge is an infrequently encountered surgical complication, more so in the head and neck region. A literature search did not reveal a previously reported case of retained or concealed surgical sponge after microscopic ear surgery. We present a unique and previously unreported case of a 25-year-old male who presented with a cystic swelling in the right supra-aural region 5 months post-modified radical mastoidectomy of the right ear. Surgical excision of the swelling revealed a retained surgical sponge. We emphasise the importance of counting surgical sponges after every surgical step to minimise the incidence of such retained surgical items.