Abstract: Objective: Oral involvement is one of the most important manifestations in systemic sclerosis. We studied clinical and radiological presentations of patients with systemic sclerosis in IRAN. Methods: This study is a prospective case series on forty patients with systemic sclerosis (29 limited & 11 diffuse form) according to ACR (American College of Rheumatology) criteria, referred to Rheumatology Research Center from 2000-2001. For every patient, 41 data surveyed. Results: The mean age of patients was 37.6 years. The mean duration disease was 6.75 years. 97.5 percent had oral involvement. Oral radiological manifestations were seen in 70 percent. The most common oral involvement was the decrease of mouth in opening position in 87.5 percent. The widening of periodontal ligament was seen in 62.5 percent. The dry of mouth and periodontal involvement were in 57.5 percent. The other manifestations included: The thigh tongue in 22.5%, lamina dura disappearing in 22.5%, root and mandibular resorption 5%. Conclusion: 1. The widening of periodontal ligament was seen more than other studies (62.2% versus 37%). 2. The resorption of mandibular was seen less than other studies (5% versus 30%). 3. The other manifestations were seen same the other studies.