Peripheral giant cell granulomas are common proliferative lesions of the oral cavity with a predilection for females. In this study, the presence of estrogen and progesterone receptors in 26 peripheral giant cell granuloma cases were studied utilizing the immunoperoxidase technique. In fourteen cases, estrogen receptor positivity was found in stromal cells. In ten of these, osteoclast-type giant cells also exhibited estrogen receptor immunostaining. Progesterone receptor expression was not detected. It was concluded that the cells forming peripheral giant cell granuloma are potential targets for estrogens and that these lesions might be conditioned by sex hormones.