Abstract: Objective To evaluate the clinical efficacy of ultrasound subgingival scaling combined with manual root planing for treatment of chronic periodontitis in elderly patients. Methods Forty elderly patients with chronic periodontitis were randomly divided into test group for treatment with ultrasound and Gracey subgingival curette for subgingival scaling combined with manual root planing and control group treated with ultrasound subgingival curette scaling (n=20). We compared plaque index (PLI), bleeding index (BI), probing depth (PD), and attachment loss (AL) between the two groups before and at 6 weeks and 12 weeks after the treatment. Results After periodontal treatment, PLI, BI, PD and AL all decreased significantly in both groups compared with the levels before the treatment (P<0.05). The patients in the test group showed significantly more obvious decrease of PD and AL than those in the control group (P<0.05), but the reduction of PLI and BI was comparable between the two groups (P>0.05). Conclusions Ultrasound subgingival scaling combined with manual root planing produces better therapeutic effect than ultrasonic subgingival scaling alone for treatment of chronic periodontitis in elderly patients.