BackgroundAs of today, the effect of coronavirus disease 2019 (COVID-19) on male fertility remains unclear. Studies published so far have partly contradictory results, likely due to very small sample sizes and heterogeneous populations.To gain a deeper understanding of the impact of COVID-19 on male fertility, we performed a prospective case–control study, in which we examined the ejaculate of 37 subjects, including 25 subjects in the acute phase of mild COVID-19 and 12 subjects who did not suffer from COVID-19. Determination of semen parameters, severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) qPCR, and infectivity analysis were performed in the acute phase of the disease and in series.ResultsSemen parameter values did not differ significantly between subjects with mild COVID-19 and the control group. The serial examination of semen parameters revealed no significant changes between 4, 18, and 82 days after the onset of symptoms. SARS-CoV-2 RNA or infectious particles could not be detected in any ejaculate.ConclusionMild COVID-19 seems to have no detrimental effect on semen parameter values.