Premature ejaculation (PE) and erectile dysfunction (ED) are the most prevalent sexual disorders in men. ED is commonly reported among patients with PE. Although recent guidelines recommend to treat ED first in men with both PE and ED, this recommendation is not based on evidence and there are limited data about the efficacy and safety of dapoxetine/sildenafil combination therapy for these patients. The aim of this study is to evaluate the clinical efficacy and safety of the dapoxetine/sildenafil combination (Dapoxil 30/50 mg film-coated tablet) in the treatment of patients with PE and concomitant ED. In a single-center, single-arm, open-label clinical study conducted between October 2016 and September 2017, 74 patients with lifelong or acquired PE and ED were included. All patients were instructed to record their intravaginal ejaculatory latency time (IELT) with a stopwatch for 4 weeks. After the screening, they were requested to complete Premature Ejaculation Diagnostic Tool (PEDT), Premature Ejaculation Profile (PEP), and International Index of Erectile Function-Erectile Function (IIEF-EF) questionnaires before the treatment. The patients received on demand Dapoxil 1-3 h before sexual intercourse for the next 4 weeks (2 days a week and no more than once a day). The patients were also assessed with global impression of change (GIC) question for the treatment satisfaction and the side effects were recorded. The study was completed with 53 patients (53/74, 71.62%). Mean age of the patients was 45.32 ± 10.05 years. At the end of the 4-week treatment period, the geometric mean IELT of the patients significantly increased (from 22.72 ± 15.16 to 68.25 ± 82.33 s; p < 0.001). Similarly, significant improvements were observed in the mean PEP index score (0.86 ± 0.72 vs. 2.36 ± 1.13; p < 0.001) and mean IIEF-EF domain score (13.17 ± 3.33 vs. 24.60 ± 3.96; p < 0.001). According to the GIC results, 81.13% of the patients were satisfied with the treatment. Non-serious adverse events occurred in 10 patients (18.87%) and 4 (7.55%) of these patients dropped out of the treatment. The most common adverse events were headache, palpitation, and flushing. The dapoxetine/sildenafil combination therapy significantly improves the IELT values and patient reported outcome measures of PE patients who also suffer from ED. Although several side effects were reported, these were mild and transient.