This study aimed to evaluate the effects of rehydration with water or acid whey, as well as the effects of bacterial-enzymatic inoculant on fermentation losses, aerobic stability, and chemical composition and in vitro digestibility of corn grain silages. The treatments consisted of corn kernels (Zea mays) ground through a 3-mm sieve and rehydrated with chlorine-free water or unsalted whey (NaCl) combined or not with bacterial-enzymatic inoculant. This was a 2 x 2 factorial completely randomized design with sources of rehydration (water or whey) and absence and presence of bacterial-enzymatic inoculant with eight replications. Water and acid whey were added to ground corn with 12% moisture in order to increase it to 35%. Rehydrated corn was ensiled in Polyvinyl chloride (PVC) minisilos and stored for 60 d. The bacterial-enzymatic inoculant used was composed of Lactobacillus curvatus, L. acidophilus, L. plantarum, L. buchneri, L. lactis, Pediococcus acidilactici, Propionibacterium acidipropionici and Enterococcus faecium, in concentrations of 1010 CFU g-1 and 5% cellulose-based enzyme complex. The aerobic exposure of silages was evaluated for 120 hours. There was interaction (P = 0.02) between the sources of rehydration and the use or not of the inoculant on the values of silage temperature during aerobic exposure. There was a difference for dry matter (DM) losses (P=0.38) between rehydrated corn silages with and without inoculant. DM losses were 37.51% higher in silage without inoculant compared to silage with inoculant (3.84% DM). There was no difference between the sources of rehydration on DM losses (P = 0.39), with a mean value of 4.99%. Corn rehydration using acid whey (P < 0.01) increased 2.19% and 31.36% DM and ash content compared to water, an average of 66.14% and 1.28%, respectively. There was no interaction (P = 0.30) between the sources of rehydration and the use of inoculants on the in vitro digestibility of DM (mean of 79.26%). The use of the bacterial-enzymatic inoculant improved the fermentation characteristics, aerobic stability and nutritional value of corn grain silage rehydrated with water or whey.