Background: Cutaneous reactions ranging from exanthems to severe adverse events have been reported in association with calcium channel blockers. Objective: Our purpose was to document cutaneous eruptions resulting from use of diltiazem. Methods: We describe three patients who experienced a cutaneous reaction (i.e., hypersensitivity syndrome reaction, pruritic exanthematous eruption, and acute generalized exanthematous pustulosis) possibly induced by diltiazem, summarize adverse reaction reports obtained from the Health Protection Branch, and review the literature on calcium channel blockers inducing cutaneous reactions. Results: Of the 315 cases of possible diltiazem-induced adverse reactions that were reported to the Health Protection Branch, 151 (48%) were cutaneous. The number of diltiazem-induced cutaneous events was significantly greater than those induced by either nifedipine or verapamil. However, no difference was found in the proportion of serious cutaneous adverse events to either of the three drugs. Conclusion: Diltiazem has been associated with a variety of cutaneous reactions that appear to occur more frequently than with other calcium channel blockers. (J Am Acad Dermatol 1998;38:201-6.)