Purpose <p>Therapy with radiotherapy in the head and neck, can be associated with gonadal damage in male survivors of cancer. To the authors’s knowledge the effect of treatments on testicular reproductive and endocrine function in nasopharyngeal carcinoma (NPC) patients has not been established.</p> Methods <p>A retrospective study of NPC analyzed hormone levels, semen parameters, sexual functioning, fertility outcome before treatment and treatment after 0, 3, 6, and 12 months.</p> Results <p>The incidence of NPC is high in Sichuan (9.5/100,000). Pre-treatment, 79.4% of NPC patients were normozoospermic. NPC were associated with worse total sperm number compared to healthy controls. There was no significant difference on sperm concentration between differentiated keratinizing group and undifferentiated non-keratinizing group. Post-treatment analyses showed that first-line treatments worsened at 0, 3 and 6 months after the end of treatment (T0, T3, T6), with total sperm number returning to previous level at 12 months.</p> <p>Sexual functions were not significantly impacted by treatment modalities, except for poorer the problem assessment of drive, erection, and ejaculation problems (DEE problems). Fertility data were available for 44 patients: Seven patients (15.9%) desired children after treatment. Six patients achieved fatherhood: 4 through natural conception and 2 following artificial reproductive techniques (ART).</p> Conclusions <p>To the authors’ knowledge, this is the first time reported the study on fertility preservation in patients with NPC. Following the azoospermia/ oligospermia induced by personalized chemotherapy regimen with NPC, spermatogenesis May take 1-2 years to recover. Nasopharyngeal cancer treatment can affect erectile dysfunction. Awareness of this issue will enable oncologists to better inform patients about the possibility of recovering fertility post-treatment and also demonstrates the importance of semen cryobanking before beginning cancer treatment.</p>