Objective:To investigate the clinical characteristics,diagnosis and treatment of male infertility associated with immotile cilia syndrome(ICS). Methods:The clinical data of six cases of male infertility associated with ICS were reviewed retrospectively. Results:The clinical features in all cases included chronic or recurrent infections of the upper and lower airways and male infertility.Sinusitis,bronchitis and bronchiectasis were found in all cases and situs inversus totalis found in two cases.Sex hormone levels,chromosome karyotype and Y chromosome microdeletion(AZF) in all cases were normal.All cases were diagnosed as severe asthenospermia by routine semen analysis.Five cases had no motile spermatozoa in semen,while there were less than 0.2%of motile sperm in one case.The total sperm count and sperm viability were normal in four cases and there were very few immotile sperm in two cases.Transmission electron microscopic examination of sperm flagellum revealed disarrangement or a partial absence of 9+2 microtubules and/or an absence of the dynein arms in six cases.The bronchial cilia in one case showed to be devoid of inner dynein arms.Five cases underwent six intracytoplasmic sperm injection(ICSI) cycles and the rates of fertilization,embryo cleavage and good quality embryos were 50.0%,69.2%and 55.6%,respectively.Two clinical pregnancies and one chemical pregnancy were achieved,with one birth of a healthy baby boy. Conclusions:The ultrastructural defect of cilia or flagellum is the most important diagnostic criteria of ICS. ICSI is an effective treatment for male infertility associated with ICS. Objective: To investigate the clinical characteristics, diagnosis and treatment of male infertility associated with immotile cilia syndrome (ICS). Methods: The clinical data of six cases of male infertility associated with ICS were reviewed retrospectively. chronic or recurrent infections of the upper and lower airways and male infertility. Inusitis, bronchitis and bronchiectasis were found in all cases and situs inversus totalis found in two cases. Sex hormone levels, chromosome karyotype and Y chromosome microdeletion (AZF) in all cases were normal. All cases were diagnosed as severe asthenospermia by routine semen analysis. Cases of no motile spermatozoa in semen, while there were less than 0.2% of motile sperm in one case. The total sperm count and sperm viability were normal in four cases and there were very few immotile sperm in two cases. Transmission electron microscopic examination of sperm flagellum revealed disarrangement or a part ial absence of 9 + 2 microtubules and / or an absence of the dynein arms in six cases. bronchial cilia in one case showed to be devoid of inner dynein arms. Five cases underwent six intracytoplasmic sperm injection (ICSI) cycles and the rates of fertilization, embryo cleavage and good quality embryos were 50.0%, 69.2% and 55.6% respectively. Two clinical pregnancies and one chemical pregnancy were achieved, with one birth of a healthy baby boy. Conclusions: The ultrastructural defect of cilia or flagellum is the most important diagnostic criteria of ICS. ICSI is an effective treatment for male infertility associated with ICS.