To compare the effectiveness of an Alloplast (Bioactive glass) and an Irradiated Bone Allograft (Rocky Mountain) as a graft material in Periodontal intrabony defects, clinically and radiologically. Materials and Method: 20 intrabony defects were treated with either an alloplast (Perioglass) or an irradiated allograft (Rocky Mountain). Clinical parameters recorded at baseline and at 6 months post-operative include plaque index, modified gingival index, sulcus bleeding index, probing pocket depth, gingival recession and clinical attachment level. Statistical analysis: All the descriptive data that include mean and standard deviation were determined. The data derived for each group was analyzed by paired and unpaired‘t’test. For all tests, a p value of <0.05 was considered significant and p value of <0.001 was considered highly significant. Results: Mean PD reduction and CAL gain in the allograft group (3.20 ± 0.91 mm and 3.20 ± 0.91 mm) were not statistically different than the allopast group (2.90 ± 0.73 mm and3.10 ± 0.87 mm). Conclusions: Within the limitation of the study, both the groups showed a significant improvement in clinical parameters from baseline to 6 months post-operative. Also, there was a comparable improvement in defect fill and defect depth at 6 months