Aim: Retrospective evaluation of the clinical effect of non-surgical periodontal therapy according the concept of full-mouth disinfection (FMD) in patients with drug-induced gingival overgrowth (GO). Material and Method: 10 patients (7 female, 32 to 73 years of age) medicated with cyclosporine and/or calcium channel blocker received oral hygiene instruction, professional tooth cleaning followed by scaling and root planning of all 4 quadrants within 24 hours. Patients rinsed with 0.12% CHX solution and brushed with 1% CHX gel for the next 2 weeks. The clinical situation was re-evaluated approximately 4 months after FMD. After completion of FMD 8 patients were assigned to supportive periodontal therapy (SPT) and monitored for a mean of 24 months. Plaque control record (PCR), gingival bleeding index (GBI), pocket depth (PD) were recorded at baseline, re-evaluation and the last SPT visit. PD sites were stratified as follows: = 4 mm, 5-6 mm and >= 7 mm. Results: The number of sites with PD = 4mm was increased significantly after FMD (56.5 to 97.4%). Concomitantly sites with 5-6 mm and >= 7mm decreased in the same interval (27.1 to 2.2%, 16.4 to 0.4% respectively). PCR and GBI also declined significantly compared to baseline. All clinical variables remained stable over SPT. Further surgical therapy was required only in one case. Conclusions: FMD and regular SPT were effective in resolving inflammation and reducing the need for surgical treatment in patients with drug-induced GO. Keywords: full-mouth disinfection, gingival overgrowth, non-surgical, periodontal therapy, cyclosporin, calcium channel blocker