Rhizopus oryzae NRRL 395 is a filamentous fungus known for its capacity to produce organic acids and enzymes. In this article, the amylases production from Rhizopus oryzae NRRL 395 by submerged fermentation in shake flasks and stirred tank bioreactor was studied. So, the effects of carbon and nitrogen source, and micronutrients addition in the production of amylases at shake flask level were evaluated. A substrate concentration of 5.0 g L-1 was found to be adequate for enzyme production (specific enzymatic activity, SEA, of 165 µmol glucose mg prot-1 mL-1) and the best enzymatic activity was obtained with the addition of FeSO4.7H2O, NaCl, CaCl2 and peptone, increasing the enzymatic activity 3.6 times over the control (SEA 605 µmol mg prot-1 mL-1). The culture was scaled to a 7-L stirred tank bioreactor, and an enzymatic activity of 251 µmol glucose mg prot-1 mL-1 was obtained. Finally, a stability evaluation of the enzymatic extract was carried out. The results obtained showed that at 30°C the glycerine was effective, maintaining the enzyme stable and active in a sample (average enzymatic activity in 3 months of test, 445 µmol mg prot-1 mL-1). To our knowledge this is the first report of amylases production in a stirred tank bioreactor and these results are promising to future investigations about amylolytic enzyme production with R. oryzae NRRL 395 in submerged culture.