Alternative sources for obtaining antimicrobial compounds have been explored, such as fruit pomace. These by-products have important compounds with different potential applications due to their vast chemical composition, rich in antimicrobial action compounds, such as phenolic compounds. In this sense, the objective was to evaluate the action of butia pomace extract against Bacillus cereus. For this purpose, hydroalcoholic suspensions (80%) of lyophilized butia pomace were were carried out in the proportion of 20% (pomace/solvent) and sonicated for 60 min. Antimicrobial activity of butiá pomace extract (BPE) was evaluated in diffusion agar. Standard frozen Bacillus cereus strain was reactivated by transferring the strains to BHI broth and incubating at 36±1 ºC for 24 h. A bacterial suspension (0.5 of the McFarland scale) was spread on Mueller Hinton medium and after 5 min, 40 µl of BPE was inoculated. Ethanol (80%) (negative control) were used and then incubated at 37±1 ºC for 24 h. The negative control did not form a zone of inhibition. Butiá pomace extract showed strong action against the pathogen Bacillus cereus with 2.33±0.04 cm of inhibition zone. The action mechanisms of extracts rich in phenolics include damage to the bacterial cell membrane and synergism of different phenolics. In adittion, bacterias Gram-positive are more sensitive to extracts rich in phenolic compounds than Gram-negative, these compounds can bind to the outer cell wall membrane and break a permeability barrier of these bacteria. New antimicrobials to combat pathogens may enhance food industry options for natural additives. In conclusion, extracts from alternative sources have great potential for use as an antimicrobial and can be applied in smart packaging or into food as a natural preservative.