The Euro-lupus project provides updated information on the epidemiologic characteristics of systemic lupus erythematosus (SLE) at the change of the millennium and defines several clinical and immunological prognostic factors. The Euro-lupus cohort is composed of 1000 patients with SLE who have been followed prospectively since 1991. Among other findings, this project has shown that a) the age at onset of the disease, the gender and the autoantibody pattern, among other factors, modify the disease expression and define some specific SLE subsets; b) most of the SLE inflammatory manifestations are less common after long-term evolution of the disease, thus probably reflecting the effect of therapy as well as the progressive remission of the disease in many patients and c) a more prominent role of thrombotic events is becoming evident affecting both morbidity and mortality in SLE.