Drip irrigation rates and organic fertilizers influenced the vegetative growth and oil content of sweet basil (Ocimum basilicum L.) plant cultivated in sandy soil, at the Experimental Farm of El-Quassasin Horticultural Research Station, Ismailia Governorate, Egypt, during the two successive seasons of 2005 and 2006. Water irrigation amount at 5096 m³/fed./season significantly increased the vegetative growth and essential oil yield/plant and feddan as compared with other rates. The poultry manure at 20 m³/fed. produced the highest values of vegetative growth (plant height, number of branches/plant, leaves/stems ratio, fresh and dry weight of herb/plant and per cut during season and the yield of fresh and dry weight of herb/fed. in the two seasons) as compared with the NPK and organic fertilization treatments. While cattle manure at the rate of 60 m³/fed. gave the highest essential oil yield/plant and fed. Irrigated basil plants with drip irrigation system at water amount of 5096 m³/fed./season combined with 20 m³/fed. poultry manure gave the best results of vegetative growth, while plants watered 5096 m³/fed./season combined with 60 m³/fed. cattle manure resulted in the highest essential oil yield/plant and feddan when compared to other combination treatments, in both seasons.