To investigate the effect of concentrated growth factors (CGFs) in human intrabony defect treatment.Thirty-one intrabony defects were randomly treated with CGFs + bovine porous bone mineral (BPBM) or BPBM alone. Probing depth, clinical attachment level and hard tissue fill were evaluated at baseline and 1 year post surgery.No differences in any of the investigated parameters were observed at baseline. At 1 year post therapy, both groups showed significant improvement in clinical parameters (p 0.05). The contents of growth factors in CGFs were statistically higher than those in platelet poor plasma (p < 0.001).Addition of CGFs significantly improved clinical effectiveness of BPBM for intrabony defect treatment.