Routine treatment for bovine mastitis is the use of antimicrobials that often promote bacterial resistance to these compounds. The use of phytoterapic medicaments have been growing in the last decade. However, many of these therapeutic options have no scientific evidence of its action efficiency against disease causing agents. The present work aimed to evaluate the antimicrobial activity of the alcoholic extract Caesalpinia ferrea Mart. fruit against bovine mastitis bacteria. The study was divided into two sequential experiments. Experiment I evaluate the potential of antimicrobial activity of the liquid aqueous solution (extract 1) and lyophilized (extract 2) of the ethanolic residue fractioned with chloroform and the aqueous solution of the ethanolic lyophilized residue (extract 3) against twelve selected bacteria (four standard and eight field strains), as a screening method for the following experiment. Experiment II used the same strains in the previous trial and evaluates the antimicrobial activity of the best extract in experiment I in eight dilutions. This study was performed using the well technique and in triplicate. Results from Experiment I report that 91.66% of the analyzed bacteria showed no statistical difference among the three extracts and confirms that the lyophilization process did not alter the antimicrobial activity of the extract 2 and 3. Extract 1 was used in Experiment I, results indicated that the antimicrobial inhibitory halo diminishes when extract dilution increases and bacteria isolated from bovine mastitis showed a minor response compared to the standard bacteria. Caesalpinia ferrea fruit extract reveals potential antimicrobial activity and a possible therapeutic option to biological assays in vivo in the bovine mastitis control.