The objective of this study was to evaluate the effect of microbial inoculant containing new strains of Lactobacillus buchneri (LB) isolated in tropical conditions on the aerobic stability (AS) of sorghum silages in different fermentation periods. A 3 × 5 factorial arrangement was used, with 3 fermentation periods (P) (20, 40 and 60 d), and 5 inoculants (I) (control, commercial inoculant, LB strains 50.4, 90.14, and 45.22), in a completely randomized design, with 4 replicates. The sorghum was mixed either with the inoculants or with distilled water (control) in approximately 7 kg and packed in plastic buckets (mini-silos). The commercial inoculant used was Lalsil AS (LAS) (Lallemand, Brazil). The strains were isolated from sorghum silages. For all treatments, the theoretical application rate was 1.0 × 10⁶ cfu/g fresh forage. After 20, 40 and 60 d of fermentation, 2 kg of silage from each silo were collected and placed in plastic buckets without a lid for 7 d at 22°C, to determine the AS. Temperatures were measured every 10 min using data loggers inserted into the silage mass at geometric center. Silage samples after 7 d of air exposure were analyzed for pH, and yeast and molds counts. The estimated means were compared by Tukey’s test considering a significance level of 0.05. The AS, pH, yeast population, and maximum temperature reached (MT) were affected (P < 0.05) by I × P interaction. Mold population was affect (P < 0.05) by both P and I effects. At d 20 of fermentation, the silages treated with LB 90.14 and 45.22 remained stable (>160 h) for 7 d after air exposure, consequently had the lowest pH, MT and yeast counts (3.59, 23.7 h and 5.22 log cfu/fresh weight, respectively). After 40 and 60 d of fermentation inoculated silages remained stable after air exposure and had the lowest pH and yeast counts. Molds population reduced throughout the fermentation period and the highest counts was observed in non-inoculated silage. The addition of LB 90.14 and 45.22 strains improved the aerobic stability of sorghum silages stored for a short period. Supported by CNPq, CAPES, and INCT-CA