It is well established that both cyclosporin and nifedipine are associated with gingival overgrowth. Although both drugs are widely used in the management of organ transplant patients, there is little information on the prevalence and severity of this unwanted effect in cardiac transplant patients. This study evaluated the gingival health of 94 dentate cardiac transplant patients, all of whom were medicated with cyclosporin as a component of their immunosuppressive therapy. Sixty-three (63) of the patients were also medicated with nifedipine. Significantly higher gingival overgrowth scores (P < 0.0001) and periodontal probing depths (P = 0.001) were observed in patients medicated with the combination of cyclosporin and nifedipine than those medicated with cyclosporin alone. Likewise, there was a significantly greater need to carry out gingival surgery on patients taking the combination (62%), than those medicated with cyclosporin alone (25.8%) (P = 0.001). Patient's age, sex, duration of therapy, gingival bleeding index, and nifedipine therapy were important determinants for both the expression of gingival overgrowth and the need for surgery. Significant sequestration of nifedipine in the gingival crevicular fluid (GCF) was observed. The concentration of nifedipine in GCF did not relate to either the gingival changes or plasma concentration of the drug. Cardiac transplant patients are at risk of developing gingival overgrowth and approximately 50% require surgical intervention. This risk increases significantly when patients are medicated concomitantly with nifedipine.