Eight patients under routine care for periodontitis received oral treatment with a form of coenzyme Q (7 / CoQ10 and 1 / hexahydrocoenzyme Q4). An unchanged plaque score showed the patients cooperated and were under plaque control. The periodontal score decreased (p less than 0.01) on CoQ treatment. Unexpectedly, the periodontal pocket depth decreased (P less than 0.05) on CoQ treatment since all patients were considered candidates for surgical intervention. Healing was so excellent 5-7 days post-biopsy that the biopsy sites were difficult to locate. The healing was viewed as extraordinarily effective. The mean value of the specific activities of the succinate dehydrogenase-coenzyme Q10 reductase of gingival biopsies increased (P less than 0.05) during treatment which could correlate with the extraordinarily healing. Treatment of periodontitis with coenzyme Q should be considered as adjunctive treatment with current dental practice.