Background: Periodontitis is a disease with multifactorial etiology and bacteria are one among these etiologic agents. Although a number of surgical and pharmacological options are available for the management of periodontitis, it still affects a large proportion of population. Recently, Metformine which is an oral anti-hyperglycemic drug has shown to increase osteoblastic proliferation .On the other hand, Clindamycin, a lincosamide antimicrobial agent which in addition to its direct antibacterial effect on ribosomal units, it has a number of unique pharmacological features that enhance its clinical efficacy and reaches high concentrations in saliva, gingival cervical fluid and bone. Patients with periodontal diseases have high levels of GCF alkaline phosphatase enzyme (ALP), so it can be used as potential marker for disease activity. Aim: of our study was to evaluate the effect of 1% metformin gel versus 2% clindamycin gel as a local drug delivery in treatment of chronic periodontitis patients, and assessment of alkaline phosphatase enzyme levels in the gingival crevicular fluid of such patients. Subjects and methods: This study was conducted on thirty patients, who were diagnosed as having chronic periodontitis. In addition to five healthy subjects were chosen as control subjects (group IV). Patients were divided into 3 groups: I, II, and III. 1% metformin gel was applied to group I, 2% clindamycin gel was applied to patients in group II, while scaling and root planning only for group III, SRP and local drug delivery was applied for patients once weekly for six weeks. Clinical periodontal parameters (periodontal pocket depth, clinical attachment loss and bleeding on probing, plaque index and gingival index) were recorded for all groups at baseline and six weeks after treatment for groupI, II and  groupIII. GCF samples were taken at baseline for all groups and six weeks after treatment for group I, II and III. The samples were analyzed photometricaly . Results: All periodontal parameters (PI, GI, PBI, PPD, CAL) and ALP levels were reduced significantly after six weeks. Conclusion: 1% percent MF was found to significantly improve clinical and parameters and decrease AlP levels in patients with chronic periodontitis, also it can be concluded that the utilization of 2% clindamycin gel in combination with SRP enhances the efficacy of nonsurgical periodontal therapy in reducing pocket depth and improving attachment levels in chronic periodontitis subjects and dereasing ALP levels, so both drugs are very useful as an adjunct treatment moreover, clindamycin gel is more effective in treatment of chronic periodontitis.