Objective. The objective of the study was to evaluate the effect of the addition of an additive and an inoculum bacterial in the chemical composition and in vitro digestibility dry matter (IVDMD) and organic matter (IVOMD) of sugarcane silage. Materials and methods. Experimental treatments were: a) sugarcane silage with 1% of bacterial inoculum and 1% of additive (SCS1); b) sugarcane silage with the bacterial inoculum 3% and 1% of additive (SCS3). The bacterial inoculum consists of 10.0% molasses, 1.0% of commercial yogurt containing Lactobacillus plantarum, L. bulgaricus, L. casei, L. acidophilus and L. bifidus, 5.0% poultry manure, 0.5% urea and 83.0% of water; the additive is formulated with 1.0% urea, 0.1% sulfate of ammonium and 0.25% phosphorus. Each treatment was determined to its chemical composition and in vitro digestibility of dry and organic matter and the results obtained were analyzed using T Student test. Results. There were differences between treatments (p<0.05) in crude protein, neutral detergent fibre, hemicellulose, ammoniacal nitrogen and pH, as well as on IVDMD, but without changes in the IVOMD, presenting the better values for SCS1. Conclusions. The 1% concentration of bacterial inoculum and additive added to sugarcane silage showed better values on in vitro digestibility of dry matter, and chemical composition, indicating an adequacy fermentation, but, at concentrations higher than 1% of additive and an inoculum bacterial decreases the quality and digestibility of the silage.