Olive mill waste water (OMWW) collected from an olive mill in El Maghara station, Desert Research Center, North Sinai Governorate, Egypt was fermented solely with one of each highly active phenol degrading bacteria namely Enterobacter asburiae and Pseudomonas aeruginosa. The fermented OMWW with E. asburiae or Ps. aeruginosa has a high level of total nitrogen, soluble nutrients (nitrogen and potassium), and low COD, BOD and phenol contentcompared to the unfermented one. Remarkable increases in different microbial counts were detected in the fermented end product than the unfermented one. A field experiment was conducted at Banger El-Sokkar area, Alexandria desert road, Egypt, using sorghum as the task crop to evaluate the fermented OMWW as biofertilizer. The results indicated that the individual addition of the fermented OMWW using Ps. aeruginosa or E. asburiae as soil drench recorded the highest figures of plant height, fresh weight of shoot, dry weight of shoot, leaf area index and seed weight compared with control. Application of fermented OMWW also, had a great positive effect on the productivity of sorghum compared to control. Microbiological analysis of rhizosphere soil indicated a remarkable increase in the total microbial counts, nitrogen fixer's counts and Pseudomonas spp. counts in plots treated only with the fermented OMWW either with E.   asburiae or Ps. aeruginosa comparing with unfermented treatment plots. Using fermented or unfermented OMWW showed positive effect on the chemical composition, sorghum in terms of nitrogen, phosphorus, potassium and carbohydrates. Results of this experiment clearly indicated that the fermented olive mill waste water can be used as natural liquid organic fertilizer to improve the productivity and chemical constituent of plants when applied as soil drench.