Objective: The purpose of this randomized، double-blind،controled trial was to evaluate the clinical and radiographic effects of 0.12% chlorhexidine digluconate gel on peri-implant (hard and soft tissues surrounding the implant) maintenance. Material and methods: Forty patients (80 implants) who received two implants at least were randomly assigned to two groups: 0.12% chlorhexidine digluconate gel as test group، and placebo without CHX as control group. Clinical and radiographic parameters were recorded at day 10، month 2، 4، and 6. Results: All clinical parameters except PPD showed better results in test group which had statistically significant reductions (P< 0.05) in modified plaque index، modified gingival index، modified bleeding index and attachment level compared to the placebo group. There were no significant differences between groups in probing pocket depth or radiographic parameter. Conclusions: The results of this clinical study indicate that twice daily use of 0.12% chlorhexidine digluconate gel may enhance the peri-implant maintenance.