Probioticated carrot and watermelon juices were produced using four different strains of lactic acid bacteria [Lactobacillus plantarum MTCC1407, Lactobacillus rhamnosus MTCC1408, Lactobacillus casei MTCC1423, Lactobacillus lactis MTCC911]. The watermelon and carrot juices were pasteurized for 30 minutes at 63^ºC and was inoculated with a 24h culture of individual lactobacilli and incubated at 37^ºC. Changes in pH, acidity, sugar content, and viable cell count during fermentation under controlled condition were measured. All of the lactobacilli were capable of growing in watermelon and carrot juices and reached a cell density of 10⁷ CFU/ml after 48h incubation at 37^ºC. Overnight cultures of Clostridium perfringens, Escherichia coli, Salmonella typhimurium, Shigella dysenteriae and Bacillus cereus were added to probioticated juices and reduction of viable cells were assayed. The viable cell counts of the four-lacticacid bacteria in the fermented carrot and watermelon juices ranged from 10⁷ to 10⁹ CFU/ml and 10⁸-10⁹ CFU/ml respectively. Antimicrobial activities of the lactobacilli cells against the test strains were also determined by measuring the diameter of growth inhibition zones. Among all the four lactic acid bacteria Lactobacillus casei was the most potent inhibitor of all the tested intestinal pathogens such as Salmonella typhimurium, Shigella dysenteriae, Bacillus cereus, Clostridium perfringens and Escherichia coli.