AIM: To systematically review the literature in order to investigate a potential association between periodontitis and halitosis. METHODS: Electronic searches were performed in four different databases: PubMed, Scopus, Web of Science and Scielo. Population-based observational studies that tested the association between periodontitis and halitosis were included. Additionally, meta-analysis, meta-regression and subgroup analyses were performed to synthesize the evidence. RESULTS: A total of 1,107 articles were identified in electronic searches; out of which, five were included within the meta-analysis. Pooled estimates revealed that individuals with periodontitis presented 3.16 times higher odds (OR 3.16; 95% CI: 1.12-8.95) of having halitosis. Meta-regression and subgroups analyses showed that criteria used for halitosis and periodontitis assessment explained nearly 45% and 24% of heterogeneity between studies, respectively. CONCLUSIONS: Positive association between periodontitis and halitosis was found in pooled results of population-based observational studies. However, this evidence is derived from cross-sectional studies.