Abstract: Systemic lupus erythematosus (SLE) as a chronic autoimmune disease has a worldwide distribution. There is a wide variation in the natural history of SLE among different ethnic and geographic groups. The aim of this study was to show the manifestations of SLE in Iranian patients. Methods: The study was on manifestations of SLE according to the database of the Rheumatology Research Center (RRC), Tehran, Iran, on registered patients during the period of 1976 to 2009. Results: A total of 2280 SLE patients (2052 female and 228 male) were studied. The female : male ratio was 9 : 1 and the mean age at presentation was 24.4  10.4 years. Prevalence of manifestations included: musculoskeletal (83.2%), cutaneous (81.1%), renal (65.4%), neuropsychiatric (23.4%), pulmonary (21.5%), cardiac (17.2%), and hematologic (66.4%) symptoms. There was positive antinuclear antibodies in 86.4% and anti- DNA in 82.3% of patients. Overlap syndrome and positive family history with other autoimmune diseases were detected in 7.6% and 3.4% of patients, respectively. Conclusion: In our patients the prevalence of cutaneous involvement was similar to those of nearby countries (with similar climate). Renal involvement was seen more than some other countries especially more than European countries, while other manifestations (such as hematologic and joint involvement) were similar to European countries (with similar ethnicity). We may conclude that genetic and/or climatic factors may lead to different presentations of lupus. Key words: epidemiology, clinical aspects, Iran, systemic lupus erythematosus.