Juvenile systemic lupus erythematosus is a rare multisystemic autoimmune disease with variable clinical manifestations, and disease onset before 16 years of age. Patients younger than 5 years are rarely affected and the age of onset may contribute to the course of disease in terms of clinical presentation, organ involvement, and serological findings. Here, we report two exemplary early-onset SLE patients, a 28-month-old patient with WHO class IIB kidney disease, arthritis, and a typical antibody constellation and an 11-month-old infant that presented with microcytic anemia, leukocytosis, arthritis, fasciitis, fatty liver disease, protein losing enteropathy, edema, and minimal change glomerulonephritis. Epidemiologic and clinical features of early-onset SLE compared to other forms of SLE are given and differential diagnoses and treatment options are discussed.