Guided tissue regeneration (GTR) in the management of the periodontal furcation invasion is effective. Recent studies showed significant clinical improvement with different materials. The purpose of this study is to provide clinical evaluations of the bone repair potential of GTR combined with a novel porcine collagen membrane in the treatment of human molar Class II furcations. Fifty-one patients, 33 males and 18 females, with no systemic disease and a mean age of 49.1 years, participated in this study after phase I periodontal therapy. Probing depth, attachment loss and radiographic examination were recorded and analyzed before and after GTR therapy with collagen membrane. In the soft tissue measurement, the periodontal pocket (PD) depth was 5.283 ± 0.283 mm before the surgery and improved to 2.631 ± 0.147 mm at 9 months after surgery (p < 0.05). Attachment loss also showed similar results. The attachment level was 5.547 ± 0.3 mm before the surgery, and 2.911 ± 0.188 mm at 9 months after surgery (p < 0.05). According to the measurements the attachment gain was 2.636 ± 0.168 mm after GTR surgery with porcine collagen membrane. According to this study, the porcine collagen membrane can perform with exceptional results in attachment level gain for the Class II periodontal furcation involvement.