In children, swallowing dysfunction and aspiration are common causes of recurrent pneumonia and can be fatal. The underlying mechanism is still unknown. In this study, we evaluated the swallowing function in 72 neonates and infants by fluoroscopy and followed the course of 39 patients for more than one year. The results of all the examinations were recorded on videotape or a digital imaging system. All 10 patients with neurologic disorder presented cricopharyngeal dysfunction. Of the 12 patients with near miss sudden infant death syndrome, 10 showed nasopharyngeal reflux, and 5 demonstrated cricopharyngeal dysfunction. In the 50 patients without neurologic disorder, 29 revealed cricopharyngeal dysfunction. Laryngeal elevation was not seen in 75%. Three of these 29 patients had no other abnormality. All patients without neurologic disorder recovered well. Seven patients demonstrated prolonged aspiration. Four of them had neurologic disorder, and the rest had near miss sudden infant death syndrome. Fluoroscopic examination showed two types of aspiration: one was caused not only by pharyngeal but also by lingual muscles. It was not associated with any neurologic disorders and the symptoms were transient. The other was caused by cricopharyngeal dysfunction and most of these patients had neurologic diseases and prolonged symptoms.