Objective: Aim of the study is to observe the occurrence of bacterial isolates from mouth ulcer swab specimens. Recurrent oral ulcer gravely frightens every day of patient's life and health. This paper talks about the recurrent oral ulceration affecting the oral mucosa by bacterial infections. Methodology: The study was carried out between April 2016 and June 2016. Mouth ulcer swab specimens were collected aseptically from patients and cultured on the appropriate bacteriological media. Bacterial isolates were identified by biochemical tests and antimicrobial susceptibility by standard methods. Result: Out of 60 samples, 45(75%) specimens were found to have bacterial growth and 15 (25%) of them showed no growth. The prevalence of bacterial spp. isolated from the mouth ulcer swab are listed as follows Acinetobacter baumanii 17(37.8%), Klebsiella pneumoniae 12(26.7%), Pseudomonas aeruginosa 08 (17.8%), Staphylococcus aureus 05 (11.1%), H.pylori 3 (6.6%). Conclusion: This study will be useful for prediction of the prevalence of pathogen in Mouth ulcer and also providing the alertness among the patients about its complications for control strategies of the pathogen.