This study concerns the form and decoration of arrows from the highlands of Papua New Guinea. The morphology of a sample of 834 arrows is described. The decorative carvings on fore-shafts and heads are analysed in terms of 13 elements and variants of these. The combinations of elements into design patterns is described and their geographic distribution analysed. Variations in both morphology and design are found to correlate with language family boundaries for the most part, but the most clearly marked boundary lies between Central and West Central language family areas.