Systemic lupus erythematosus (SLE) in children and adolescents is a multisystem autoimmune disease with a great variability in disease presentation and course. The diagnosis of SLE is based on the clinical and laboratory features consistent with this illness in the absence of other autoimmune disease that could explain the findings. At the time of diagnosis of SLE, most, but not all, patients have at least four of the American College of Rheumatology classification criteria for SLE. This article summarizes available epidemiologic data, clinical patterns, approaches to investigation and treatment, and recent outcome data.