The microbiological safety of fresh produce is a significant concern of consumers and industry. After applying at an inoculated level (about 10 6 CFUg −1 ) of E. coli O157:H7 and Salmonella enterica serovars Typhimurium on shredded iceberg lettuce and water samples individually, they were stored at 4°C for 14 days and 22°C for 7 days to monitor the growth and survival of pathogens. The results showed that at the end of 4°C storage, populations of two pathogens in lettuce and water decreased approximately 1logCFUg −1 . However, microbial levels on shredded lettuce increased 3logs within 3 days at 22°C. Vinegar (acetic acid) had been used to reduce populations of foodborne pathogens in foods; hence, the antimicrobial effect of rice vinegar on the survival of E. coli O157:H7 in inoculated lettuce (10 4 and 10 7 CFUg −1 ) is examined in this study. Results were observed that the treatment of inoculated lettuce (10 7 CFUg −1 ) with commercial vinegar containing 5% acetic acid (pH 3.0) for 5min would reduce 3logs population at 25°C. Less than a 1-log decrease in bacterial numbers was recovered during 5min exposure to 0.5% (pH 3.26) acetic acid.