We describe 2 cases of obstructive azoospermia associated with situs inversus and sinopulmonary infection due to ciliary defects. Electron microscopy of testicular sperm flagella demonstrated normal morphology with nine peripheral doublets surrounding a central pair and complete sets of inner and outer dynein arms. Electron microscopy of the nasal mucosa revealed partial defects of the dynein arms of cilia, although the "9+2" morphology was preserved. Our cases were considered unique variants of Young's syndrome but also had characteristic features of Kartagener syndrome, and thus support the hypothesis that Young's syndrome has a genetic etiology similar to that of Kartagener syndrome.