Erythema nodosum (EN) seems to occur in children more rarely than in adults. It still remains the most frequent acute panniculitis, for which the diagnosis is almost always clinical. In a retrospective study of 27 pediatric patients, we have attempted to clarify the clinical spectrum and prognosis of this disease and discuss the differential diagnosis of nodular eruptions on the lower limbs of children. In almost half the patients of our series, the cause of EN remained undetermined. Streptococcal infections (usually of the pharynx) were the most common cause of EN in children (22% of patients in our series), followed by Yersinia infection in about 15% of patients. Tuberculosis, an important cause in the past, was never found, but must always be excluded. A benign course was noted in all patients. Erythema nodosum is easily recognized clinically, but other subcutaneous lesions, especially nodular vasculitis and Schönlein-Henoch purpura, have to be excluded by pathologic study, in cases of atypical presentation or long duration.