Background <p>Metabolic Bariatric Surgery (MBS) is highly effective in promoting weight loss and weight loss maintenance in patients with obesity. Worldwide, the predominant MBS was sleeve gastrectomy (SG), followed by the Roux-en-Y bypass, while One-anastomosis gastric bypass (OAGB, mini-gastric bypass) only accounted for 4.3% of the surgeries. Conversely, In Israel alone in 2020 OAGB accounted for 63.7% of all bariatric surgeries, followed by SG. This provides a genuine opportunity to compare postoperative complications amongst these bariatric procedures. </p> Aim <p>In this retrospective study we reviewed medical records of 2765 patients who have undergone SG or OAGB in the Herzliya Medical Center (HMC) between the years 2018–2020, and compared 30-day postoperative complications between the two procedures. </p> Methods <p>The 30-day timeframe was divided into two periods, the first consisting of hospitalization and included complications such as need for blood or plasma infusion during surgery, cardiorespiratory complications. The second period extended from discharge until the end of the 30th postoperative day and included complications such as surgical wound infection and other infections. </p> Results <p>During hospitalization, 1.7% of SG patients had complications and 2.2% of OAGB patients had complications (<i>p</i> = 0.374). In the second period, 3.8% of SG patients and 4.1% of OAGB patients had complications (<i>p</i> = 0.907). </p> Conclusion <p>These results indicate that there was no difference in the 30-day postoperative complication rate between these two types of bariatric procedures.</p>