The relationship between nitrogen and other components in kikuyu grass (Pennisetum clandestinum) from long-established pastures was investigated. Leaf material, when compared to stem tissue, was higher in total organic nitrogen and protein content, but lower in non-protein organic nitrogen, nitrate, potassium, lignin, and non-structural carbohydrates. The in vitro digestibility of leaf material was higher than that of the stem. A high nitrogen content was associated with high protein and low lignin contents, which favours digestibility. However, it was also associated with a high nitrate content which tended to reduce the digestibility in vitro. The conditions under which the nutritional value is optimized without unduly sacrificing yield, should urgently be investigated.