Objectives: To describe clinical and laboratory features of systemic lupus erythmatosus (SLE) in children with anticardiolipin (aCL) at Children Hospital No.1. Method: Prospective, descriptive study. Results: There were 15 patients with aCL (50 percent): 6 cases with IgG-aCL, 8 cases with IgM-aCL, and 1 case with IgG and IgM-aCL in 30 systemic lupus erythematous patients in Children Hopital No.1 from March 2006 to March 2007. Mean age of patients is 12.87 + or - 2.26 years old. Most of them were female (86.67 percent). 60 percent of cases had systemic hypertension, 40 percent with heart injuries, 73.3 percent with platelet depletion, and 40 percent with thrombotic microaangiopathy (TMA). Conclusion: aCL, an antibody which nas strong association with APS, has a high percent in SLE patients. Clinical and laboratory aspects of SLE in children with aCL are charactered by systemnic hypertension, platelet depletion, heart injuries, and TMA.