BACKGROUND: Zika virus (ZIKV) sexual transmission and prolonged viral shedding in semen have been previously reported, suggesting a strong viral affinity for genital tissues. A transient impact of ZIKV on male fertility was shown in animal and human studies. METHODS: Adult male patients with confirmed ZIKV infection diagnosed in the city of Araraquara, Brazil during the epidemic season of 2016 were invited one year after the acute infection to respond to a questionnaire of genital symptoms and to provide a semen sample for molecular ZIKV testing and spermogram analysis, as well as a serum sample for hormonal testing. RESULTS: 101 of 187 tested patients had positive ZIKV RT-PCR in plasma and/or urine samples (54%, 72 women and 29 men). Of 15 adult male participants for whom telephone contact was successful, 14 responded to the questionnaire of genital symptoms and six consented to provide a semen sample at a median of 12 months after the acute infection. We report abnormal spermogram results from patients one year after confirmed ZIKV infection. CONCLUSIONS: Our findings suggest a possible long-term detrimental effect of ZIKV infection on human male fertility that has to be further explored in well-characterized samples from cohort studies conducted in ZIKV-endemic areas.