The PRESERFLO® Microshunt procedure offers a safe and effective alternative to trabeculectomy procedure. The adjuvant use of anti-vascular endothelial growth factor (VEGF) with trabeculectomy has been well studied, yet little is known on the effect and safety of anti-VEGF agents used as an adjunctive therapy in PRESERFLO® procedures. To compare the outcomes of PRESERFLO Microshunt procedure using either mitomycin C (MMC) alone versus MMC augmented with bevacizumab in patients with open angle glaucoma to a follow-up time of 6 months. Retrospective observational single-center single-surgeon study. Patients' records of patients who consecutively underwent PRESERFLO Microshunt at Queen Victoria Hospital, United Kingdom, were examined. From December 2018 to January 2020, eligible patients underwent PRESERFLO Microshunt implantation with MMC alone (0.2-0.4 mg/ml), whereas from February 2020 to January 2022, patients underwent PRESERFLO Microshunt implantation with MMC (0.2-0.4 mg/ml) and adjuvant intracameral 0.1 ml of bevacizumab (1.25 mg/0.05 ml). Efficacy outcomes were analyzed, including changes in intraocular pressure (IOP) and changes in medication use. Postoperative complications and postoperative interventions were also reviewed. A total of 75 eyes were included in the analysis, 38 eyes received MMC alone, whereas 37 eyes received MMC combined with bevacizumab. There were no statistically significant differences in the demographic or clinical profile of patients between treatment groups.Both strategies were effective in terms of IOP lowering (baseline vs 6 months postoperatively: 20.0 (6.8) mmHg vs 12.8 (3.7) mmHg in the MMC group; 23.6 (6.9) mmHg vs 11.9 (4.2) mmHg in the MMC+ bevacizumab group; p < 0.001 in both comparisons). Mean anti-glaucoma medication use also reduced significantly from baseline with no difference between both groups. A higher proportion of patients required postoperative interventions (5-FU injection, needling, and bleb revision) in the MMC alone group (N = 16; 42.1%) compared to the MMC+ bevacizumab group (N = 4; 9.9%) which was statistically significant (Pearson's χ2 test; p = 0.002). Adjuvant use of bevacizumab in MMC-augmented PRESERFLO Microshunt procedure is at least as effective as MMC alone but helps reduce rates of postoperative interventions.