OBJECTIVE: To determine if the epidemiological, clinical and laboratorial features observed among hyperthyroid patients with Graves disease, influence the appearence of Graves Ophtalmopathy (GO). MATHERIAL AND METHODS: Analitical, observational and cross-sectional trial of 97 hyperthyroid patients. 69 patients completed the inclusion criteria. RESULTS: GO is more frequent among women (1, 1: 1) and in the fifth decade, although none of them were significant. Simultaneous onset between systemic complaints and GO, in the first six months, had statistical significance. Tobacco did correlate significantly with development of GO. Severe involvement of GO are more frequent in males. Exophtalmos was present in 27% of patients. CONCLUSIONS: The first six months of onset of clinical manifestations of Graves disease and smoking habit should alert us about the risk of GO development. Exophtalmos is ...