In asymptomatic infertility patients, no significant relationship was found between the presence of antisperm antibodies (ASA) in ' serum and in semen samples (IgG and/or IgA ASA), differentiated with the mixed antiglobulin reaction (MAR), and the microbial colonization of ejaculates covering a broad spectrum of microorganisms. Likewise, there was no significant association of ASA with microbial findings in patients' female partners, who also presented without symptoms of genital tract infection and were screened at the same time. Furthermore, ASA in semen (IgG and IgA) were not significantly related to several potential markers of subclinical male sexual gland infection or inflammation (leukocytes, PMN elastase, albumin, CSc) evaluated in aliquots of the same ejaculates used for immunological testing.