We characterized endocrine profiles and semen quality in spinal cord injury subjects using noninjured normal and infertile subjects as controls. Compared to normal controls, spinal cord injury subjects had lower serum levels of luteinizing hormone and follicle-stimulating hormone. Subjects with spinal cord injuries between the T8 and T10 levels had a higher incidence of hormone outliers compared to subjects with injuries at other levels. Sperm motility and per cent normal sperm morphology were lower in spinal cord injury subjects compared to normal controls but not to infertile control subjects. Spinal cord injury subjects with elevated follicle-stimulating hormone levels were azoospermic. We conclude that endocrine abnormalities are likely to accompany spinal cord injury but may not be the sole mechanism contributing to impairments in semen quality.