Fentanyl is a synthetic opioid agonist, which interacts primarily with the mu-opioid receptor. Fentanyl is approximately 75-100 times more potent than morphine in analgesic activity. These patches are designed to deliver fentanyl at a constant rate (25, 50, 75 and 100 microg/h), and require replacement every 72 hours in Turkey Abuse of transdermal patches is reported. Oral, rectal, inhalation and intravenous abuse of fentanyl patches were identified in many cases . Fentanyl patch addiction cases are reported rarely . E.G., 40 years old, female patient was married and housewife, had two children. Breast cancer was diagnosed 5 years ago. Left mastectomy, chemotherapy and radiotherapy were administered. Liver metastases from breast cancer were identified 2 years later and transdermal fentanyl was administered for treatment of chronic cancer pain. Transdermal fentanyl was began with 25 mcg initial dose, 2 months later increased to 50 mcg dose/day and continued through 3 months. When fentanyl treatment was stopped, withdrawal symptoms consisting of yawning, rhinorrhea, tachycardia, sweating, tremble, restlessness and sleeplessness were observed. Patient could not tolerate these symptoms and began to use transdermal fentanyl again. She wanted to use 50 mcg/day, but 25 mcg was prescribed by her physician. Then, dosage was decreased to 12.5 mcg before her hospitalization to Erenkoy AMATEM clinic. She was admitted to our clinic with withdrawal symptoms. Buprenorphine-naloxone 4mg/day treatment was started to patient. Buprenorphine-naloxone was decreased to 2 mg/day and stopped when withdrawal symptoms were disappeared. Patient described depressive symptoms. Duloxetine 30 mg/day was initiated and increased to 60 mg/day. She was discharged with improvement. As seen above DSM-5 criterions for “opioid dependence” were provided for our patient. Transdermal fentanyl patch can be used for the treatment of chronic pain including cancer pain and non-cancer pain. Environmental and biological factors are the risks for opioid dependence and abuse. Opioid dependence in males is 1.5 times more common than females. Comorbid depression, anxiety disorder, attention deficit-hyperactivity disorder and posttraumatic stress disorder increase the risk for opioid dependence. Depression is seen often in cancer patients. Antidepressant treatment must be initiated to patient for depressive symptoms. Clinicians must be careful when using transdermal fentanyl because of the dependence risk. Oncologists should consult to psychiatrists for treatment management.