Purpose: To evaluate diathermy to minimize sclerotomy leakage during small-gauge vitrectomy and prevent ocular hypotony.Methods: This observational prospective study included 327 patients (327 eyes) who underwent diathermy to close the sclerotomy sites during 23-gauge pars plana vitrectomy (PPV). All patients were operated by a single surgeon (ED) and evaluated at 30 and 60 days postoperatively. Patients with glaucoma, topical/systemic steroids use exceeding 30 days, ocular inflammation, or trauma were excluded. Chi-square, Kruskal-Wallis, Fisher Exact test, and multivariate statistical analyses were performed to evaluate potential risk factors. The primary outcomes were open sclerotomies, leakage, and ocular hypotony.Results: Sclerotomies remained open in 12 (3.6%) and 2 (0.6%) patients, respectively, at 30 and 60 days postoperatively, revealing no case of ocular hypotony. Leakage only occurred in four patients (1.2%) during week 1 postoperatively. Multivariate analysis indicated that additional vitreoretinal surgeries and longer surgeries were risk factors for persistent sclerotomy opening.Conclusion: Diathermy was safe and feasible to close sclerotomies. Vitreoretinal surgery reoperations and longer surgeries were the most significant (