Fentanyl, a synthetic, highly selective opioid ${mu}$-receptor agonist, is 50 to 100 times more potent than morphine. The low molecular weight, high potency, great transdermal permeation rate and lipid solubility of fentanyl make it very suitable for transdermal administration. Durogesic is a novel matrix transdermal system providing continuous systemic delivery of fentanyl. In recently, there are many reports that misused or overused fentanyl transdermal patches result in severe intoxication of fentanyl. We present a case of fentanyl toxicity with misused durogesic transdermal patch and discuss the safe and appropriate application of the patches. In conclusion, fentanyl patches should be used in opioid tolerant patients and prescribed at the lowest possible dose and titrated upward as needed. All patients and their caregivers should be educated safe application of fentanyl patches and advised to avoid exposing the patches application site to direct external heat sources, such as heating pads, or electric blankets, heat lamps, sauna, hot tubs, and others. In addition, concomittant medications that affect fentanyl's metabolism should be avoided.