BACKGROUND: Vallecular cysts are an unusual cause of congenital stridor. OBJECTIVE: To describe the imaging findings in five patients, with emphasis on the usefulness of sonographic studies. MATERIALS AND METHODS: Between 1990 and 2007, five patients with a cystic lesion situated in the anterior neck, at the vallecular space, were seen in our institution. Clinical records and imaging findings were retrospectively reviewed. RESULTS: All patients presented with persistent inspiratory stridor that was present from the first week of life. Neck US was performed as part of the investigations in four and showed a vallecular cyst. The diagnosis was confirmed with flexible bronchoscopy in four infants and CT in one; all were resected. Pathology showed a multilayered epithelial border with normal thickness and differentiation; there were no signs of malignancy. CONCLUSION: Although vallecular cysts are very rare, they should be considered in the differential diagnosis of congenital stridor. When the commonest causes have been ruled out, neck US may be diagnostic. The diagnosis can be confirmed with flexible bronchoscopy or further imaging such as CT or MRI.