Thirty-four cardiac patients, treated with nifedipine (Adalat, Procardia) during a period of 1 year or more, developed slight to severe gingival epithelial hyperplasia, and five cases presented nodular overgrowth of the gingiva. In terms of histopathologic and clinical morphology, nifedipine-induced gingival hyperplasia is similar to that known to be caused by phenytoin (Dilantin). Both drugs have the ability to alter calcium metabolism. We believe that the hyperplastic condition is related to calcium imbalance.