Many techniques have been attempted to alter the negative relationship between grain yield and grain nitrogen (N) concentration in wheat. Better understanding of the varietal and yearly variation of these traits requires a detailed knowledge of the physiology of ear development from the pre-anthesis phase onwards and of the requirements for N fertilization by the developing apex. Two cultivars with contrasting grain yield and protein concentration characteristics were studied under greenhouse conditions in order to establish the effects of N on spikelet and floret development and protein synthesis in spring wheat ( Triticum aestivum L.). The development of wheat was divided into pre- and post-anthesis phases. Two N fertilizer treatments were applied: sufficient for normal growth (C) and excess (E) nitrogen application. Development of the inflorescence, grain yield, N uptake, grain N concentration and protein quality of flour were measured. The application of N fertilizer during the pre-anthesis phase affected fertile floret number more than spikelet number. Pre-anthesis N application increased grain yield and tiller initiation. Post-anthesis nitrogen supply resulted in an improved grain N concentration. Grain N was higher in grain formed on tillers. The contribution from the tillers was also important for protein quality. The use of N fertilization for the stabilization of both grain yield and grain N concentration is discussed.