PURPOSE: Global obesity rates have surged, necessitating effective interventions beyond traditional bariatric and metabolic surgery (BMS). Endoscopic Sleeve Gastroplasty (ESG) has emerged as a minimally invasive alternative, addressing limitations of eligibility criteria and patient reluctance associated with BMS. This study aims to present a 3-year experience with ESG, focusing on its mid-term efficacy in weight loss. MATERIALS AND METHODS: A retrospective, single-center study included 143 consecutive ESG patients (BMI > 30 kg/m or > 25 kg/m with obesity associated-diseases) from February 2019 to March 2023. Data on demographics, comorbidities, operative details, and follow-up outcomes were collected. The primary outcome was %TWL ≥ 15% at 12 months. Secondary outcomes were an optimal clinical response (OCR) at 24 and 36 months defined by %TWL ≥ 10% or %EWL ≥ 25%. RESULTS: ESG demonstrated a mean %TWL of 14.37% at 12 months, aligning with previous studies. Early postoperative complications were minimal (2.1%), with no mortality. Follow-up revealed a peak in weight loss at 9 months, but mid-term OCR was achieved in 41.2% at 3 years. The learning curve showed efficiency improvements after 26 procedures. CONCLUSION: ESG proves effective at one year, with a %TWL of 14.37%. However, mid-term efficacy beyond 12 months remains challenging, raising questions about the durability of weight loss. Despite a low complication rate, strategies for maintaining a long-term OCR, including potential repeat ESG, warrant further investigation.