Study design <p>Retrospective cohort study.</p> Objectives <p>To evaluate cauda epididymal sperm aspiration (CESA) as a sperm retrieval method for men with spinal cord injury (SCI) related paraplegia who were unable to ejaculate.</p> Setting <p>Retrospective observational study conducted at Saint Mother Clinic, a private fertility center in Japan, using data collected from 2010–2023.</p> Methods <p>CESA was performed in 69 men with complete lower-body SCI and anejaculation. Men were categorized according to successful or unsuccessful sperm retrieval. Clinical and hormonal characteristics, sperm quality, and ART outcomes were analyzed.</p> Results <p>CESA successfully retrieved sperm in 42 men (60.9%). Median FSH was 4.6 mIU/mL in successful cases and 12.9 mIU/mL in unsuccessful cases. FSH was the strongest predictor of successful retrieval, with a receiver operating characteristic-derived cutoff of 5.95 mIU/mL. Among successful cases, median sperm concentration was 32 million/mL and median motility was 56%. Among the 35 men who proceeded to ART after successful CESA, 56 clinical pregnancies and 45 live births were achieved across 146 embryo transfer cycles.</p> Conclusions <p>In selected men with SCI who are unable to ejaculate, CESA can retrieve large numbers of highly motile sperm suitable for cryopreservation and repeated ICSI use. By reducing the need for repeated surgical retrievals, CESA may offer a practical and less invasive alternative to testicular sperm extraction.</p> Trial registration <p>UMIN000055045, registered July 22, 2024. https: //center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000062867</p> <p></p>