The aim of the present study was to investigate the potential of date wastes as substrate for the production of Baker's yeast and Citric acid using strains of Saccharomyces cerevisiae ATCC 1102 and Aspergillus niger ATCC 16404 and the determination of optimized production conditions. Submerged fermentations was carried out in a fermentor of 3 litters capacity. So, the obtained results show that the optimal Baker's yeast production was obtained at dilution rate of 0.22 h^-1. On the other hand, the strain of Sacccharomyces cerevisiae SC-DB-A12 produced high yield biomass compared to other strains. Also, the use of ammonium phosphate provides better biomass yields compared to other nitrogen source. Concerning the citric acid production, the optimal fermentation period was 144 h. The maximum citric acid production was obtained at 30°C and at 150.0 g L^-1 of sugars. In the same way, the addition of methanol at concentration up to 3.0% resulted in a marked increase in the citric acid production. In addition, the optimum pH for maximum citric acid production was 3.5. The aeration rate kept at a level of 1.0 L/L/min was found to be optimum. Finally, the best results were observed when 2.5 g L^-1 ammonium nitrate and 2.5 g L^-1 of potassium phosphate were added into the medium. In summary, a maximum citric acid production i.e., 126.4 g L^-1 was obtained at these optimal conditions. It is concluded from these results that the date wastes could serve as a potential substrate for Baker yeast and Citric acid production.