【Objective】To investigate the feasibility and effectiveness of using ultrasound- guided cricopharyngeal （CP）botulinum toxin（BTX）injection to treat cricopharyngeal dysfunction after brainstem infarction.【Method】A patient with dysphagia caused by subacute lacunar infarction in the right pontobulbar junction was diagnosed with incomplete opening of cricopharyngeal muscle by videofluoroscopic swallowing study（VFSS）. After precisely locating the CP muscle with catheter balloon and ultrasound，we injected BTX（25 U/0.8 mL）into the left CP muscle using the out-of-plane ap? proach technique.【Result】After the injection，the patient made great progress in swallowing. He was able to eat porridge independently without bucking on the 5th day，while soft rice on the 8th day and sip water. Two weeks after the injection， VFSS showed that the bolus progressed into the esophagus fluently without the route getting narrow or broken off，and hardly found residue in pharynx，which suggested that the CP muscle could open properly. 【Conclusion】Cricopharyngeal injection of BTX guided by ultrasound is a safe and effective way to treat cricopharyngeal dysfunction after brainstem infarction ，which is also convenient to operate and deserves to be disseminated after the further studies proves its effectiveness