The periodontal status of 54 renal transplant recipients and 52 patients with chronic renal failure receiving hemodialysis was evaluated and compared with that of systemically healthy subjects matched for age, sex, social status and the number of teeth present. The renal transplant recipients had been receiving immunosuppressive (IS) drug therapy since the time of transplantation. Both of the renal patient groups had significantly higher plaque index scores than the respective controls. By contrast, the renal transplant recipients showed significantly lower periodontal scores and pocket depths. However, there was no significant difference between the hemodialysis group and the corresponding healthy controls with regard to mean periodontal index score and pocket depth. No significant differences could be found among the three groups with regard to mean sulcular bleeding index score or gingival index score. Within the IS group, no relationship was found between the duration of drug therapy and the various periodontal parameters. The observed variations among the groups studied appear to suggest modulation of periodontal condition by both general health status in patients with chronic renal failure and the IS agents used in renal transplant recipients.