Port site hernia (PSH) following laparoscopic procedures is a rare but serious complication. The aim of this study was to evaluate the rate of PSH after laparoscopic sleeve gastrectomy (LSG), and the efficacy of closure of the port site as a means of preventing PSH. A retrospective analysis was performed on 386 patients who underwent LSG between December 2009 and January 2015. 352 (91.2%) of the patient were followed up for at least 24 months. In the first 206 patients, the fascial layers of the trocar incisions were not closed, while in the next 146 cases, routine closure of the trocar sites was performed. The patients were reviewed in relation to demographics, comorbidities, complications, percentage of excess weight loss, and rates of PSH. The total cohort consisted of 220 female and 132 male patients with a mean age of 36.2 ± 12.3 years. Demographic data, initial BMI, and comorbidities were similar for the patients in both groups. The closure of the fascia was caused by the prolonged duration of the operation with no significant difference. The unclosed fascial defects were associated with a significantly increased incidence of PSH (1.3 vs. 3.9%, p < 0.05). All of the patients who experienced PSH had at least one comorbidity, and no complication was noted in the fascial closure cases. It was found that the rate of PSH after LSG is not as low as previously thought, and that routine closure of fascial defects at port sites may result in a decreased PSH rate.