Open tension-free techniques of hernia repair using synthetic meshes are a well-accepted practice with an excellent patient comfort and a low recurrence rate. Otherwise, the influence of the resulting fibrosis on testicular perfusion is still unclear. In this study, the effect of prosthetic materials on testicular perfusion was evaluated using Duplex ultrasonography. Twenty-four patients participated in this prospective study. A total of 26 procedures were performed under general anaesthesia. All patients underwent standardized scrotal ultrasound study and Duplex imaging preoperatively, 1, 3 and 9 months after the procedure. Scrotal volume, vein diameters and modifications of arterial blood flow, evaluated by the acceleration index (AI), of the funicular and peritesticular vessels were measured. No statistically significant differences were found between preoperative and postoperative measurements which included testicular blood flow parameters and testicular volume. Moreover, in some cases, a testicular flow improvement was detected after the operation. Furthermore the side of the hernia and the position of the mesh slit (lateral or upper) to allow the passage of cord structures did not influence the results. So far there is no evidence for a significant impairment of funicular structures after open hernia repair using tension free techniques.