Historically, spinal-cord injured men have been considered virtually sterile because of ejaculatory dysfunction commonly resulting from their injury. Assisted ejaculatory techniques, however, have overcome the problem of sperm transport and have allowed both the establishment of pregnancy through artificial insemination and the assessment of their semen quality. Most studies have noted the presence of asthenozoospermia in the setting of normal sperm concentration following electroejaculation or vibratory stimulated ejaculation. Thus far, little attention has been given to the basis for the frequent finding of asthenozoospermia, and the possibility of sperm autoimmunity in this group has not been adequately studied. In nine spinal-cord injured men, reproductive evaluation was performed consisting of hormonal measurements, testicular biopsy, and indirect immunobead tests for sperm autoimmunity. A mean sperm concentration was 144 +/- 185 x 10(6)/ml. However, the mean motile concentration was 33 +/- 62 x 10(6)/ml. Indirect serum immunobead showed positive IgG or IgA titers in 3 of 8 patients. Because of the disproportionately high incidence of an immunologic factor in spinal-cord injured men compared to able-bodied infertile men, sperm autoimmunity should be considered among the important causes underlying seminal dysfunction following spinal cord injury.