The aim of this study was to determine the impact of long-term escitalopram treatment on semen parameters of patients with lifelong premature ejaculation (PE). Between November 2008 and January 2010, patients admitted to urology outpatient clinic with a self-reported complaint of PE were evaluated. Medical and sexual history of patients were recorded and patients with lifelong PE (a total of 25 patients) who met the International Society of Sexual Medicine definition were asked to record their intravaginal ejaculatory latency time (IELT) for 1 month, complete Premature Ejaculation Diagnostic Tool (PEDT) questionnaire and give semen samples. Afterwards, patients received 10 mg escitalopram daily for 12 weeks and were invited for control visits at first and third month of treatment. During control visits, PEDT was administered again whereas IELTs were recorded and semen samples were re-examined. PEDT scores, arithmetic means of IELTs and results of semen analyses, which were recorded at baseline, first and third month were compared. At the third month of treatment, a significant increase in mean IELTs and a significant decrease in PEDT scores were detected. However there was a significant decrease in sperm concentration, motility and morphology when compared with the baseline semen measures. Daily escitalopram treatment effects the semen parameters of patients with lifelong PE. Further investigations with larger series are needed to see whether other serotonin reuptake inhibitors have similar side effects and to expose the exact mechanism underlying it. Different treatment modalities should be suggested to patients who desire fertility.