To longitudinally evaluate the effects of compliance during periodontal maintenance therapy (PMT) on C-reactive protein (CRP) levels and its relation to periodontal status. A subsample comprising of 30 matched pairs was taken from a previous 6-year longitudinal study under PMT. Pairs were composed of one regular (RC) and one irregular (IC) compliers, matched by age and sex. Periodontal parameters and plasma samples were collected at 3 times: T1[prior to active periodontal therapy (APT)], T2(after APT), and T3(after 6years). CRP plasma levels were quantified using ELISA. RC presented better clinical periodontal status, lower recurrence of periodontitis (sites with PD ≥4mm and CAL ≥3mm, together with the persistence and/or presence of BOP and/or suppuration, during any of the subsequent recall evaluations) and significant reductions in CRP levels over time [(T1: RC=3.64±2.13 and IC=3.92±2.02mg/L) and (T3: RC=2.12±1.39mg/L and IC=3.71±1.82mg/L)]. Logistic regression analysis demonstrated that individuals with periodontitis recurrence presented 2.19 higher chances of presenting altered CRP levels (values ≥3mg/L- T2 to T3) than those without periodontitis recurrence (95%CI:1.16-3.27; p=0.017). Higher CRP plasma levels were associated with higher recurrence of periodontitis and worse clinical periodontal parameters among IC when compared to RC.