This study was conducted in the two successive seasons of 2005/2006 and 2006/2007 at the Experimental Farm of Floriculture, Faculty of Agriculture, Assiut University. The aim of this study was to investigate the effect of three rates of each of nitrogen (0, 50 and 100 kg/fed.), active dry yeast (0, 2 and 4 g/l) and tryptophan (0, 50 and 100 ppm) on the growth, fruit and oil yield and chemical composition of fennel plants. The obtained results revealed that the application of nitrogen, active dry yeast and/or tryptophan resulted in a significant increase in vegetative growth, fruit and oil yield as well as fruit content of total carbohydrates, N, P and K compared to the controls. It was interesting to observe that the application of active dry yeast at 4 g/l as biofertilizer with 100 ppm tryptophan as organic nitrogenous source gave nearly equal results to those obtained with the high level of mineral nitrogen fertilizer (100 kg N/fed.) alone. Also, the application of active dry yeast at 4 g/l or tryptophan at 100 ppm combined with 50 kg N/fed. resulted in a significant increase in all studied parameterscompared to the high level of nitrogen alone. The maximum vegetative growth and flowering, fruit and oil yield as well as fruit nutrient content were obtained from the combined treatment of 50 kg N/fed. + 2 or 4 g/l active dry yeast + 50 ppm tryptophan