PURPOSE: Peri-implantitis is caused by biofilm adhering to the implant. It has been shown that bactericidal electrolysis products are generated when a low direct current is applied to a titanium implant used as the anode. The hypothesis of this study was that low-current electrolysis would eradicate viable bacteria in a simulated subgingival multispecies biofilm adhering to a titanium implant surface. MATERIAL AND METHODS: Biofilms consisting of eight anaerobic species were grown on pellicle-coated titanium discs with sand-blasted, acid-etched, large-grit (SLA; Straumann, Basel, Switzerland) surface. After 40.5 hours of growth, discs were treated with 10 mA for 10 minutes in an electrolytical setup with physiological saline and gelatin. RESULTS: Low direct current at discs used as the cathode caused a reduction of three to four orders of magnitude in viable counts, while no viable bacteria were recovered from anode discs (Mann-Whitney U-test, p < .01). Confocal laser scanning microscopy in combination with a live/dead stain showed biofilm detachment at the cathode and reduced viability at the anode. CONCLUSION: Electrochemical treatment of diseased implants appears to be promising and well worth investigating further.