Aim: The aim of present study was to evaluate the effects of chicory leaf extract on serum oxidative stress markers, lipid profile, and periodontal status in patients with chronic periodontitis. Methods: In this double-blind, randomized controlled clinical trial 40 patients with chronic periodontitis were allocated to intervention and control groups. The intervention group received a 1-gram chicory leaf methanolic extract capsule twice daily for 8 weeks. In the control group, participants received a placebo capsule (containing 1 gram wheat flour) twice daily for 8 weeks. All participants had nonsurgical periodontal therapy during the study. Anthropometric measurements, dietary intake, total antioxidant capacity (TAC), malondialdehyde (MDA), uric acid, lipid profile (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]), and pocket depth (PD) were assessed before and after intervention. Results: The results showed that mean serum TAC, uric acid, and HDL-C increased and mean serum MDA, TG, LDL-C, and TC decreased significantly in the intervention group compared to their baseline and the control group post-intervention. A significant difference was observed in mean PD between the two groups. Conclusion: Chicory leaf extract as an adjunct nutritional approach with nonsurgical periodontal therapy may be helpful in controlling periodontal status.