Gingival overgrowth, dental plaque, and gingivitis were assessed by means of standardized semiquantitative indices in thirty renal transplant patients undergoing immunosuppression with cyclosporin-A (Cy-A). Radioimmunoassay techniques were used to determine Cy-A in serum samples and in parotid, submandibular, and whole saliva samples from each patient. A significant positive correlation was found between gingival overgrowth scores and both dental plaque and gingivitis scores. A significant positive correlation was found between whole-saliva Cy-A and both plaque and gingival overgrowth scores. No such correlation was found when parotid Cy-A or submandibular Cy-A was considered. This was attributed to differences in saliva-collection methods, and a possible role of dental plaque as a local reservoir of Cy-A is proposed.