The objective of this study was to determine the effect of inoculation with Lactobacillus buchneri and/or Lactobacillus hilgardii on the fermentation and chemical composition of sorghum silage. Sorghum plants were harvested at 27% DM from 4 different plots, chopped and ensiled separately in vacuum-sealed nylon-polyethylene bags (40 × 61 cm) for 30 and 90 d. Treatments included application of (1) deionized water (CON) or inoculants containing (2) Lactobacillus buchneri (1.5 × 10⁵ cfu/g, LB); (3) Lactobacillus hilgardii (1.5 × 10⁵ cfu/g; LH); and (4) Lactobacillus buchneri and L. hilgardii (1.5 × 10⁵ cfu/g of each inoculant, LB+LH). Samples were collected from each replicate on d 0, 30, and 90 and analyzed for chemical composition, microbial counts, and aerobic stability. Data from each ensiling period were separately analyzed with the GLIMMIX procedure of SAS for a completely randomized design. Fresh forage samples had 6.6 log cfu/g of LAB and a pH of 5.74. Inoculation did not affect (P > 0.05) DM loss, pH, VFA concentration or aerobic stability (>500 h) of d 30 samples. However, inoculation increased LAB counts compared with CON after 30 (9.02 vs. 6.88 log cfu/g) or 90 d (8.49 vs. 7.08 log cfu/g) and greater counts were for LB and LB+LH. Concentrations of NDF and ADF were increased by LB+LH after 30 or 90 d and by LH after 30 d. Inoculation had no effect (P > 0.05) on DM loss, pH, or lactic acid concentration after 90 d but it increased (P = 0.004) acetic acid concentration, decreased (P = 0.0014) lactic to acetic acid ratio (1.9 vs. 3.7) and increased aerobic stability relative to CON (>576 vs. 346 h). Inoculating sorghum forage with LB, LH, and LB+LH improved LAB counts after 30 or 90d of ensiling and improved aerobic stability after 90 d of ensiling; however, fermentation profile was not improved.