Recently, bacteriophages have been renewed attention as bactericidal agents due to their specificity to the target bacteria and no harmful effects. This study aimed to investigate the effect of bacteriophage-antibiotic combination against Salmonella Typhimurium and also evaluate the development of antibiotic resistance in Salmonella Typhimurium when treated with bacteriophage-antibiotic combination. The susceptibilities of S. Typhimurium to cefotaxime, chloramphenicol, ciprofloxacin, erythromycin, streptomycin, and tetracycline were increased by 13%, 10%, 22%, 25%, 9%, and 12% in clear zone sizes, respectively, in the presence of bacteriophage P22. Minimum inhibitory concentrations (MICs) were decreased in the presence of bacteriophage P22, showing cefotaxime (0.06 to 0.03 mg/mL), chloramphenicol (4 to 0.25 mg/mL), ciprofloxacin (0.016 to 0.008 mg/mL), erythromycin (64 to 8 mg/mL), streptomycin (64 to 16 mg/mL), and tetracycline (2 to 1 mg/mL). The number of S. Typhimurium treated with the bacteriophage-antibiotic combination was significantly reduced by more than 5-log after 12-h of incubation at 37oC. The combination treatments could reduce the development of antibiotic resistance in S. Typhimurium compared to the control and single treatment (bacteriophage or antibiotic alone). The application of bacteriophages combined with antibiotic can be a promising strategy to control antibiotic-resistant bacteria. This study sheds light on possibility of using bacteriophage-antibiotic combination as therapeutic agents.