Voriconazole is a triazole antifungal drug that is used to treat invasive fungal infections, especially aspergillus. Here, we report two children who had severe bradycardia associated with voriconazole at a dose of 12 mg/kg per day. Bradycardia resolved in 24 hours in both after decreasing the dose to 10 mg/kg per day. Heart rates were in normal limits on follow-up. Bradycardia may be a side effect of voriconazole treatment in children under immunosuppressive treatment. Heart rate should be monitored in patients receiving voriconazole and other triazole treatments.