About 30% of patients with anti-glomerular basement membrane antibody (anti-GBM) disease may also have concomitant antineutrophil cytoplasmic antibody (ANCA) positivity. Both these processes can affect the kidneys and/or lungs. We report a case of a patient with dual positivity for anti-GBM antibodies and ANCAs who underwent both pulmonary and kidney biopsies. There is only 1 previous report in the literature of a patient with dual positivity for anti-GBM antibodies and ANCAs who also underwent both pulmonary and kidney biopsies. Our case is unique in that our patient had dual positivity and also had evidence of unique tissue injury mediated by both antibodies in both the kidneys and lungs. We discuss the significance of dual-antibody positivity based on reported cases.