The production of small ruminants is an important economic activity of the brazilian Northeast, but some diseases have a high prevalence in this region, such as caseous lymphadenitis (CL), caused by Corynebacterium pseudotuberculosis. The treatment of CL is often ineffective, which justifies the search of new active principles from plants, mainly of the region, to have an accessible treatment. For this reason, the present study was carried out to evaluate the in vitro antibacterial activity of Annona squamosa, Azadirachta indica, Allium sativum, Prosopis juliflora and Portulaca oleracea against C. pseudotuberculosis. Agar well diffusion assay (AWD) and broth microdilution - to determine minimum inhibitory concentration (MIC) and bactericidal concentration (MBC) - evaluated the antimicrobial activity. The highest antibacterial potential was obtained by ethanolic extracts of A. indica leaf (MIC 0,12 mg/mL for 2 strains), A. squamosa stalk (MIC 0,55 mg/mL for 3 strains) and shell (MIC 0,6 mg/mL for 3 strains). These extracts also presented the highest inhibition zone in AWD (30 mm, 38 mm and 32 mm, respectively). A. squamosa and A. indica have high antimicrobial potential against C. pseudotuberculosis.