The purpose of this systematic review was to establish if patients suffering from periodontal diseases present differences in the expression or production of cationic antimicrobial peptides in saliva, gingival fluid, and periodontal tissues. Periodontal diseases are among the most common chronic diseases worldwide and share similar etiological or risk factors (genetic and/or environmental) with other systemic disorders. Over the last decade, an increasing number of publications have suggested the implication of antimicrobial peptides (AMPs) in periodontal and oral tissues conditions. Literature searches were conducted through MEDLINE-PubMed and EMBASE databases which identified 1267 publications. Only clinical studies that focused on assays of the expression and/or production of AMPs in human adult oral fluids (gingival crevicular fluid or saliva) or in oral tissues were retained and finally seventy-four publications meeting inclusion criteria were included. Cathelicidin, α- and β-defensins 1-3 are the most documented AMPs regarding periodontal status. Significant correlations between clinical periodontal indexes (PD, CAL) and/or bacteriological index and LL37 level were retrieved. Data remain inconsistent between the studies for hBDs mainly due to heterogeneity of the results, periodontal disease diagnostic criteria and assaying technique employed. Given their role in innate immunity and their antimicrobial functions, LL-37 and α-defensins may be eligible as periodontal clinical biomarkers and could be an interesting way for therapeutic development.