^{Background and Aim: Probiotics could have benefits on oral health, partially through modifying oral cavity microflora. The purpose of this study was to investigate the effect of a commercial probiotic yogurt consumption on oral halitosis.}  

^{Material and Methods: This clinical trial was conducted on 44 volunteers suffering from halitosis with oral cavity origin. The subjects were given 200 ml probiotic yogurt daily for a period of two weeks. One examiner evaluated subjects’ mouth odor at baseline and after two weeks using organoleptic assessment (5 point scale: 0= no, 1= brief, 2= medium, 3=severe, and 4= very severe) at 10 and 50 cm distances. Data were analyzed by SPSS software using Wilcoxon test (&alpha=0.05).}

^{Results: Baseline mean organoleptic scores (10 and 50 cm) were 2.63±1.12 and 1.95±1.23, which decreased to 1.45±1.10 and 0.95±0.93 at the end of study (P< 0.001).}

^{Conclusion: consumption of probiotic products could be considered as an effective strategy for improvement of halitosis with mouth origin.}