Two field expermiments were carried out in which onion (Allium cepa) plants cv. Giza 20 were grown in clay soil supplied with different organic fertilizers i.e. poultry, sheep, cattle manures, sewage sludge and town waste composts, at the rate of 10, 20 or 30 tons/fed. for each. Also the inorganic fertilizer was applied at the rate of 400, 300 and 150 kg/fed. as amonium sulphate (20.5% N), calcium superphosphate (15.5% P₂O₅) and potassium sulphate (48 % K₂O), respectively (the recommended rates). The pervious treatmemts were compared with control (without fertilization). The organic fertilizers significantly increased vegetative growth characters, bulbs yield and quality. Vegetative growth characters were determined at 4 months after transplanting. Applying 30 tons/fed. of poultry manure, 20 tons/fed. of poultry manure or in organic fertilizers caused the heighest plants (without significant differences among them), in the first season. In the second season the heighest plants were obtained by adding 30 tons/fed. of poultry manure, 30 tons/fed. of sheep manure or 20 tons of poultry manure in descending order.                 The highest values of number of leaves and fresh weight of leaves / plant were obtained with supplying 30 tons/fed. of poultry manure or 30 tons/fed. of sheep manure, in the two seasons. Dry matter percentage of leaves and bulb fresh weight were the highest by application of 30 tons/fed. of poultry manure or 30 tons/fed. of sheep manure in the two seasons. The lowest values of bulbing ratio were obtained by addition of 30 tons/fed. of poultry manure or 30 tons/fed. sheep manure. In general increasing the rates of organic fertilizers increased their effect on vegetative growth. Application of sewage sludge followed by town waste composts gave the lowest values of vegetative growth characters. Using 30,20 tons/fed. of poultry manure followed by 30 tons/fed. of sheep manure produced the highest bulbs yield and average fresh weight of bulb. Dry matter percentage of bulb at harvest were the highest by using 30 tons/fed. of poultry manure 30 tons/fed. of sheep or 30 tons/fed. of cattle manure in the first season. On the other hand the highest values were obtained by applying 30 tons of poultry manure 30 tons of sheep manure or inorganic fertilizer, in the second season. Total soluble solides and total carbohydrates contents were the highest by adding 30 tons/fed. of poultry manure, 20 tons/fed. of poultry manure or 30 tons/fed. of sheep manure in descending order, in the two seasons. The effect of cattle manure on bulbs yields and quality was moderate. The lowest values of the yield and quality were obtained with the application of sewage sludge and town waste composts, in the two seasons. Application of 30 tons/fed. of poultry manure caused the highest N, P and K contents of leaveas and bulbs. Whereas, appliction of 10 tons/fed. of town waste compost resulted in the lowest N,P,K content of leaves and bulbs.                 The highest contents of (Zn, Mn and Fe) in leaves and bulbs of onion plants were obtained by applying sewage sludge compost, cattle and sheep manures, respectively. The highest contents of Cu, Cd and Pb in leaves and bulbs were obtained by addition of sewage sludge followed by town waste composts. In general, applying poultry manure at the rate of 30 tons/fed. is recommended for onion bulb production.