Propylthiouracil (PTU), used to treat Graves' disease, occasionally induces a lupus-like syndrome. A 39-year-old woman developed clinical manifestations of systemic lupus erythematosus with rash, serositis, myocarditis, and acute renal insufficiency, associated with serologies for lupus, after 3 wk of exposure to the drug. Renal biopsy revealed diffuse proliferative lupus nephritis. This article reviews the side effects of PTU and the literature on PTU-induced nephrotoxicity. Possible mechanisms and management of drug-induced lupus nephritis are also reviewed. To facilitate early and specific intervention, clinicians should be aware of the propensity of PTU to cause lupus-like syndromes with renal involvement.