We report a case of conversion disorder after spinal anesthesia. A 16-year-old healthy woman underwent arthroscopic surgery under spinal anesthesia. She showed tremor all over and it did not stop. We sedated her with propofol during the operation. After the operation, her involuntary tremble continued. We consulted with a pediatrician who diagnosed her as conversion disorder. Magnetic resonance imaging and computed tomography were performed to rule out some pathological changes and abnormality in her head. As a result, Rathke cleft cyst was suspected but it could not explain this episode. We consider that her stress for the operation under spinal anesthesia caused this episode. In a case of a younger patient, it is necessary to consider mental support. And we need to suspect conversion disorder when we see tremor during operation under regional anesthesia.