Idiopathic collapsing glomerulopathy is an aggressive variant of focal segmental glomerulosclerosis (FSGS) seen primarily in adults. Its etiology is unknown. Nearly identical pathology is seen in association with nephrotic syndrome in human immunodeficiency virus type 1 (HIV-1)-infected patients, raising the possibility that viral infection plays a role in pathogenesis. This is supported by the recent discovery of parvovirus B19 DNA in some cases of idiopathic collapsing glomerulopathy. We report a case of collapsing glomerulopathy in a 16-year-old girl who presented with steroid-resistant nephrotic syndrome and pulmonary tuberculosis. In the absence of the usual associations (adult age group, African-American race, or history of intravenous drug abuse), infection is the sole known risk factor in this case. This lends support to the hypothesis that immune dysregulation due to infection per se, rather than infection by specific viral agents, may lead to collapsing glomerulopathy in susceptible individuals.