Melissa officinalis L. (sweet balm, lemon balm) is a medical and aromatic plant which is a member of Lamiaceae family. It is used by people for its hypnotic, sedative and spasmolytic effects. In this report, a case is discussed about Melissa officinalis dependency and deprivation symptoms after cessation of use. The patient was a 30 years old, male, married and had a college degree. He applied our emergency department with complaints of restlessness, tremor, distractibility, sweating for about 24 hours. Patient was evaluated by psychiatrist because of his anxiety and there was no organic reason related to his complaints. In mental state examination patient’s affect was distressed, his mood was anxious, he had no psychotic symptoms, no appetite and he had insomnia for two days. In his neurological examination there weren’t any pathological findings except his resting tremor in his both hands. During interview, patient expressed he was in an important period of exams. It was learned from the patient that he bought sweet balm plants in tea form (Melissa tea) from herbalist two months ago and drank it at every night. He started to drink one or two cups of Melissa tea per day. After 20 days, he increased the amount of tea to three or four cups per day. He expressed that he had stopped taking this tea three days ago and his complaints started after he had stopped intake tea. His symptoms were thought as deprivation symptoms and clonazepam treatment was started (1x3 drops per day). Clonazepam dose was reduced gradually in 10 days and after that it was stopped. His complaints improved completely at the end of the ten days. There were no symptoms of deprivation in control examinations at first and third months. This case showed that using Melissa officinalis plant might be a reason of dependence of this plant. In researches about Melissa officinalis, it is emphasized that this plant had two modes of action on human metabolism: This plant inhibits the activity of acetylcholinesterase (AChE) and aminobutiric acid transaminase (GABA-T) enzymes, which cause an increase in the cholinergic and GABAergic inşuence, respectively. With these mechanisms it is understood that Melissa officinalis has sedative, anxiolytic, hypnotic effects as well as its favorable effects on cognitive functions. Also it is shown that this plant’s positive potency is equal to that of 0.125 mg triazolam per day on people who has sleep disorders. Consequently although Melissa officinalis is preferred by patients instead of drugs because of being natural, it should not be ignored that it might have dependency risk.