Recently, the use of over the counter (OTC) drugs are highly recommended. However the usability of packages and devices has not been well studied. We conducted usability tests with 20 children and 20 adults. Five commonly used OTC intranasal drug delivery devices, one group of devices containing 30 ml liquid (A, B, C) and the other containing 15 ml (D, E), were tested. To evaluate the usability of nasal devices, 5 scoring choices were selected by the subjects for opening caps, stability of holding with fingers, and ease of pushing levers. Some 7-year old children could not hold and push devices A and B. Parents chose smaller devices (D, E) for their children. All parents assessed that it was necessary to see the actual devices when they choose nasal devices for their children. The study of usability for OTC drugs and devices is an important issue for safe medication.