A new spiny puffer (Diodontidae) Chilomycterus spilostylus, is described from ten specimens, from the northern Red Sea, the South China Sea and the Philippine Islands. C. spilostylus is distinguished from all other Indo-Pacific Chilomycterus by colour, spine morphology, and spine arrangement. All spines are fixed and short, and many on the head have four rather than three subdermal bases. A single medial frontal spine is located between the nostrils and three spines are over the eye. We tentatively conclude that the form incorrectly called Cyclichthys echinatus (Gronow) is the pelagic juvenile stage of C. spilostylus.