This investigation was conducted in the two successive summer seasons of 2010 and 2011 on sweet pepper plants "Madir" hybride at a private farm at Sahragt El-Soghra near Mansoura, Dakahlia Governorate, Egypt to study the effect of two sources of organic fertilizers (chicken manure and compost), biofertilizers (a mixture of Azotobacter chroococcum and Bacillus circulans bacteria and Mycorrhiza fungi), some foliar application treatments (seaweed extract, yeast extract and humic acid) and their interaction on vegetative characteristics and chemical constituents of leaves. Results indicated that the highest values of vegetative parameters, i.e., plant height, number of leaves, number of branches, leaf area, fresh and dry weights as well as chemical constituents of leaves, i.e., chlorophylls (Chl. a, Chl. b and total Chl. a+b), N, P and K percentages were recorded when plants supplied with chicken manure at 2.43 ton/fed. as compared with compost in the two seasons. Plants in the presence of biofertilizers recorded better growth performance and higher values of chemical composition in leaves than untreated plants in the two seasons. Comparing the effect of foliar applications, seaweed extract at 2.5 ml/L or yeast extract at 5 g/L recorded the highest significant values of most formentioned parameters compared with the control in both seasons. in addition, spraying humic acid at 1.5 ml/L came in the second order and significantly increased number of branches, fresh and dry weights in both seasons and leaf area in the second season as compared with the check treatment. The best results of both vegetative parameters and chemical constituents were recorded when plants fertilized with chicken manure at 2.43 ton/fed. and sprayed with either seaweed extract at 2.5 ml/L or yeast extract at 5 g/L in the presence of biofertilizers in both seasons. Therefore, this treatment could be recommended for improving sweet pepper performance under similar conditions of this study.