The objective of this study was to investigate the effect of red bell pepper on the survival and growth of Escherichia coli O157:H7 in ground beef. Four different strains of Escherichia coli O157:H7 (944, E0019, F4546, and Cider) were used in this study. Each strain was inoculated into 100g of ground beef to reach the initial inoculum level of approximately 3 log CFU/g. The inoculated ground beef was then mixed with red bell pepper, at the level of 5 % (W/W). Ground beef samples without treatment were used as controls. Samples were stored at 37 °C, collected at 0 and 8 h, stomached for 120 seconds, serially diluted, and plated onto BHI agar plates. Plates were incubated at 37 °C for 24 hrs. Results showed that red bell pepper extract had a significant antibacterial activity against all 4 strains in ground beef. The red bell pepper extract reduced the population of Escherichia coli O157:H7 by approximately 1.2 log CFU/g in an average compared to the control sample. Our result suggests that red pepper could be used as an effective preservative against this pathogen in ground beef.