It has been established that smoking is an important risk factor for the initiation and progression of chronic periodontitis (CP). This study investigates the effects of phase I periodontal therapy and adjunctive flurbiprofen administration on prostaglandin E(2) (PGE(2)) and thiobarbituric acid reactive substance (TBARS) levels in gingival crevicular fluid (GCF) samples from smoker and non-smoker patients with CP.