Purpose: The open new simplified totally extraperitoneal (ONSTEP) technique for the repair of inguinal hernia was presented some years ago with promising initial results regarding chronic pain. We conducted a randomized clinical trial investigating the ONSTEP technique versus the Lichtenstein technique with focus on postoperative pain. The aim of this paper was to report the results regarding chronic pain from follow-up at 6 and 12 months for the participants in the ONSTEP versus Lichtenstein trial. Methods: This study was conducted as a randomized double-blinded clinical trial in male participants with primary unilateral hernias, having surgical repair of their hernia at one of five participating general surgical departments. At surgery, participants were allocated (1:1) to the ONSTEP or the Lichtenstein technique for inguinal hernia repair. Participants were followed up with questionnaires at 6 and 12 months. The primary outcome was the proportion of patients with substantial pain-related impairment of daily functions at 6- and 12-month follow-ups. Results: From April 2013 to May 2014, 290 male patients were included in the study. Regarding follow-up for pain, a total of 259 patients (89%) completed the 6-month follow-up and a total of 236 patients (81%) completed the 12-month follow-up. Regarding pain at the 6- and 12-month follow-ups, no difference was found between groups. Two patients operated with Lichtenstein technique developed severe disabling chronic pain postoperatively, which was not seen in the ONSTEP group. Conclusion: The ONSTEP technique was not superior to the Lichtenstein technique regarding chronic pain following repair of primary inguinal hernias in males. Trial registration: https://clinicaltrials.gov NCT01753219