Background: There are no published studies regarding the role of the plasminogen (PLG) system in familial Mediterranean fever (FMF), FMF-associated secondary amyloidosis, or chronic periodontitis (CP), although recent limited data have focused on the association between FMF and chronic periodontitis. Therefore, the aim of this study was to evaluate the serum, salivary, and gingival tissue levels of PLG in patients with CP, FMF, and amyloidosis.