A strapless nasal interface device is disclosed. The device is used in conjunction with CPAP, BIPAP, ventilators, or any other suitable device. The device includes a body with a passageway to a ventilating tube, exhalation holes, and a passageway to nostril interface tubes. The nostril interface tubes include a nasal interface element which is an expandable, compressible material such that the user can compress the element, insert it into the end of the nostril and allow it to expand to hold the tube in place. Alternatively, the nasal interface elements are held against the outer edge of the nostrils. Optionally, a skirt is included at the outer side of the nostril to aid in sealing against air leaks. Optionally, flaps are included to assist in holding the device in place, such as side flaps, a front flap, or both. The front flap may be adherable to the exterior of the nose and optionally includes resilient strips to open the nasal passageway. Alternatively, a nose cover is adhered to the nose and side attachment flaps secure the device to the nose cover. Thus, the device requires no additional straps or headgear in order to maintain the device in operable position during sleep.