Presently, utilization of protein hydrolysates containing antibacterial activity leads to the development of new medical approach. In order to increase value added of vegetables, this research was aimed to screen antibacterial activities of protein hydrolysates from various parts of some vegetables in Thailand. The proteins were extracted and digested with pepsin. Finally, the antibacterial activities were tested using Broth Microdilution Assay against 15 bacterial strains which cause human infection for example gastrointestinal and respiratory diseases. The result showed that protein hydrolysates from Ipomoe aaquatica (water morning glory) gave the best antibacterial activity by determining from inhibition percentage. It might be a new approach as a medical treatment against antibiotic resistant bacteria in the future.