Aim and Background. Bacteria of the species Bacillus pumilus produce a large number of biological compounds which are active against bacteria and fungi. This study was designed with the aim of isolation, screening and optimization of antimicrobial production of Bacillus pumilus against four pathogenic microorganisms.

 Materials and Methods. For the initial screening of antimicrobial activity against four pathogenic microorganisms , agar disk diffusion method and TSB medium and for the production of antimicrobial compounds, synthetic medium and agar well diffusion method is used. To obtain the maximum production of antimicrobial compounds, pH (6-9), incubation period (0-72 hours) and glucose concentration (1-5 ٪ ) are well considered. Data were analyzed by SPSS and ANOVA tests.

Results. Maximum production of antimicrobial compounds by standard and isolated strain of B. pumilus was observed after 48 hours of incubation at 37^oC, pH 7 and 3% glucose against four microbial strains. 

 Conclusion. B. pumilus species might be a potential candidate for the production of antimicrobial compounds in the future.