An improved adjustable nasal dilator device (1) insertable within the nasal cavity of a human being to improve the flow of air through the nasal passage. The device includes a body (2) comprising a top (3) and bottom (4) frame ends interconnected by a series of spaced flexible ribs (5). The top and bottom frame ends are open and substantially circular, and the diameter of the bottom frame end is greater than the corresponding diameter of the top frame end to provide a body shape for convenient insertion within a nasal cavity.