The objective of this study was to determine the frequency of Metabolic Syndrome (MetS) in patients with SLE and to analyze the association of MetS with traditional risk factors for CHD and lupus characteristics. In this cross-sectional study the frequency of MetS was determined according to the National Cholesterol Education Program Adult Treatment Panel III in patients with SLE. The association of MetS with the traditional risk factors for CHD not included in the syndrome definition, and with lupus characteristics was examined. The mean age (sd) of the 162 females patients was 38.8(11.2) years. The frequency of MetS was 32.1%. Abdominal obesity and hypertension were the two most common components of the syndrome (86.5% each) followed by low levels of HDL-cholesterol (84.6%), hypertriglyceridemia (69.2%) and hyperglycemia (15.4%). MetS was significantly associated with older age, family history of CHD, obesity, postmenopausal status, LDL-c ≥100mg/dl, and higher Framingham risk score. Lupus characteristics associated with MetS were history of nephrotic proteinuria during follow-up and current cyclophosphamide use, higher modified SLEDAI-2k, higher damage index score (SLICC/ACR), and older age at lupus diagnosis. In the logistic regression analysis, obesity, LDL-c ≥100mg/dl, older age at lupus diagnosis, higher damage index and nephrotic proteinuria were independently associated with MetS. We conclude that MetS diagnosis was frequent in patients with lupus. The syndrome was associated not only with traditional risk factors for CHD, confirming the clustering of those risk factors, but also with lupus characteristics. Some of those factors, especially LDL-c ≥100mg/dl and age at lupus diagnosis, have been associated with atherosclerosis in lupus patients. Lupus (2010) 19, 803—809.