Statement of the Problem: The presence of bacterial biofilms is the major cause of gingivitis and periodontitis, their mechanical removal is not often enough. Therefore, laser therapy and photodynamic therapy can be effective as adjunctive treatment.Purpose: This study aimed to evaluate the impact of these treatments on the level of gingival crevicular fluid (GCF), inflammatory mediators, and periodontal clinical status.Materials and Method: In this clinical trial, three quadrants were studied in 12 patients with chronic periodontitis aged 30-60 years. The clinical parameters were recorded and GCF samples were taken. After the first phase of periodontal treatment, one of the three quadrants was determined as the control group, one was treated by diode laser, and one underwent photodynamic therapy. The clinical parameters were recorded 2 and 6 weeks later. The data were statistically analyzed by using Friedman, ANOVA, and LSD post-test.Results: Significant reduction was observed over time in the level of Interleukin-1β (IL-1β), Interleukin-17 (IL-17), clinical attachment loss, and pocket depth in the three treatment groups (p< 0.000). The three treatment methods significantly reduced the IL-1β and IL-17 at the baseline, up to 2 weeks, and 2-6 weeks (p< 0.05). Diode laser and photodynamic therapy significantly decreased the average bleeding on probing over time (p< 0.000 and p< 0.002, respectively).Conclusion: Laser and photodynamic therapy reduced the inflammatory mediators (IL-1β and IL-17) and improved the clinical symptoms. Keywords ● Cytokines  ● Laser Therapy  ● Photosan