Osteoid osteoma was first described as a specific disease entity by Jaffe (1935). It is an uncommon benign bone lesion and accounts for about 10 per cent of benign bone tumours (Dahlin, 1957). Osteoid osteoma has not been reported in the calvarium according to a recent review (Karlsberg and Kittleson, 1964). This paper describes a case of osteoid osteoma in the squamous temporal bone. A twenty-four year old female was admitted for investigation of discomfort in her right shoulder and forearm. While in hospital, a review of her symptoms revealed that she also complained of a mild left sided frontal headache.