In several mammals, a direct connection between the nasal cavity and the oral cavity is a common finding. The structure is named the nasopalatine duct (NPD). It has been hypothesized to be functional in terms of transportation of odorants from the oral cavity to the nasal cavity. In humans, the NPD exists during embryological development. The connection between the nasopalatine infundibulum and the incisive fossa is typically closed at the time of birth. We present the case of a 24-year-old man who presented with a persistent NPD. By means of a thin, soft tube, it was possible to probe the NPD. Magnetic resonance imaging revealed a bony gap between the hard palate and the alveolar process of the maxillary bone with a length of 16 mm and a width of 6 mm. In light of the literature of the past 500 years, this represents a rare finding of a persistent NPD.