Restless legs syndrome (RLS) is a neuropsychiatric syndrome that may lead to chronic insomnia and may impair the quality of sleep. The typical clinical features are motor restlessness, difficulty falling asleep, dysesthesia, the requirement of unbearably moving extremities. RLS can be caused by vitamin deficiencies, anemia, secondary to certain drugs and an unknown number of reasons. Antidepressant drugs that have been reported may trigger RLS. A case with mirtazapine induced RLS will be presented. A 57-year-old female was admitted to psychiatry outpatient clinic with the existing complaints such as reluctance, inability to enjoy life, feeling worthless, attention deficiency, loss of concentration, insomnia, anxiety and waking up suddenly lasting a month. The physical examination was unremarkable. Results of laboratory tests such as biochemical parameters, complete blood count, thyroid function tests, vitamin B12, vitamin D and folic acid levels were in normal range. On psychiatric examination; she was conscious, oriented and her cooperation was şuent and understandable. She had anxious affect and depressive mood. Her thought content was related to symptoms of insomnia, anhedonia was detected and there was no hallucination and delusion. The diagnosis was compatible with Major Depressive Disorder according to DSM-V. Mirtazapine 15mg/day was initiated and techniques for sleep hygiene were recommended. She was evaluated using Hamilton Depression Rating Scale (HDRS) (33/51); Beck Depression Inventory (BDI) (48/63); Beck Anxiety Inventory (BAI) (52/63) and Pittsburgh Sleep Quality Index (PSQI) (10/21) at the first application. At the end of third week, treatment scores were as follows; HDRS (20/51), BDI (21/63), BAI (23/63) and PSQI (7/21). The patient’s depressive and anxiety symptoms were decreased compared with the first application. However sleep quality had not improved enough. Furthermore additional complaints such as increasing sensations of tingling, burning and restlessness in the legs, urge to get out of the bed had arose especially in the evening. These additional symptoms were compatible with RLS. Therefore, pramipexole 0.25 mg/day was added her treatment. Compared with the first application, her scores were as follows; HDRS (7/51), BDI (9/63), BAI (4/63) and PSQI (3/21) at the end of the sixth week of treatment. Follow-up of this patient is ongoing. Association of insomnia and depressive symptoms are frequently reported and it may be related to each other. Drugs with a high sedative property such as mirtazapine may be used in the treatment of both conditions. Some case reports that use of pramipexole in the strengthening treatment of depression was presented in the literature. In this case RLS was aroused after the treatment of mirtazapine, this situation was thought it might be mirtazapine induced RLS. After addition of pramipexole to the mirtazapine treatment, RLS symptoms decreased as well as anti-depressive treatment was strengthened. The purpose of this case is to remind that RLS might occur due to mirtazapine and can be treated with pramipexole successfully.