Background and Aim: Bacterial enteritis occurred in neonatal lambs, is an economically important disease that can cause high morbidity and mortality in lambs, therefore, emergency antibacterial treatment is necessary. Malva sylvestris L. plays an important role in traditional remedies for medicinal properties. The present study aimed to evaluate the antibacterial activity of M. sylvestris on bacterial pathogens isolated from the stool of diarrhetic lamb. Materials and Methods: The antibacterial activities of M. sylvestris hydroalcoholic extract (MSHE) were evaluated by agar diffusion and microbroth dilution methods against isolates of Salmonella enterica (n=10), Escherichia coli (n=10) and standard strains S. enterica PTCC 1709-CIP104115, E. coli PTCC1270. Results & Conclusion:The results of plant extract efficiency against clinically isolated reported as Minimum Inhibitory Concentration (MIC) test and Minimum Bactericidal Concentration (MIC) test toward E. coli (MIC: 11.56±0.0 mg×mL -1 and MBC: 21.25±0.0 mg×mL -1 ) S. enterica (MIC: 42.50±0.0 mg×mL -1 and MBC: 80.00±0.0 mg×mL -1 ). The conclusions of this study indicated that M. sylvestris revealed antibacterial properties and this plant could be a good candidate for the generation of new wide spectrum antibacterial agents.