Periodontitis with a deep pocket can be treated with open flap debridement, and regenerative therapy can be done if there is an intrabony defect. The aim of this study was to compare the clinical and radiographic outcomes of flap surgeries with or without bone graft+membrane. Forty-eight chronic periodontitis patients underwent flap surgery with or without bone graft+membrane. All patients had a probing pocket depth (PPD) of ≥6mm. Secondary data from each patient's dental record was used to obtain initial PPD, clinical attachment loss (CAL), gingival recession (GR) and bone height (BH) via radiography. After treatment, we re-examined patients to measure these data. Mean scores for PPD, ΔGR, CAL and BH no n-bo ne graft groups were 3.93±2.05 mm, 1.64±1.73 mm, 2.28±2.52mm and 1.27±1.29mm; the bo ne graft gro up's mean scores were 3.95±1.59mm, 1.10±1.26mm, 2.85±1.9 mm and 2.28±2.23. A Mann-Whitney test showed that PPDs between groups were not significantly different. CAL, GR and BH showed a significant difference between the bone graft and non-bone graft groups. The results of this research show that periodontal surgery with and without bone graft+membrane can reduce pocket size, and bone graft + membrane offers an additional benefit in terms of CAL gain, GR loss and BH gain