OBJECTIVE: To investigate the relationship of the mutation of the spermatogenesis-associated gene KLHL-10 with azoospermia, oligospermia and asthenospermia. METHODS: Genomic DNA was extracted from the peripheral blood samples of 325 patients with idiopathic azoospermia (n = 11), oligozoospermia (n = 196) or asthenospermia (n = 118) and 100 fertile male controls. KLHL-10 mutations were detected for all the DNA specimens by PCR, DHPLC and sequencing techniques. RESULTS: A novel heterozygous mutation (C88 --> A) was identified in exon 1 from 1 oligospermia patient and 3 fertile male controls and another one (C424 --> A) confirmed in exon 2 from 4 fertile controls, 3 oligospermia patients and 1 asthenospermia man. Both of the mutations were synonymous, but neither missense mutation nor microdeletion of the KLHL-10 gene was found. CONCLUSION: The KLHL-10 gene is not a major contributor to azoospermia, oligospermia or asthenospermia in Chinese population. The value of this gene in the diagnosis of male infertility remains to be further investigated.