A 41-year-old woman who had been taking paroxetine began taking tramadol for bilateral ankle pain. A few days later, the patient presented acutely with both feet tremors. During a mental arithmetic task, index-finger pointing posture briefly appeared on the left side. Co-administration of paroxetine and tramadol increases the risk of serotonin toxicity. This is the first reported case of index-finger pointing posture which was associated with serotonin toxicity.