Background: Periodontal disease is a chronic disease of the oral cavity comprising a group of inflammatory conditions affecting the supporting structures of the dentition. Numerous markers in saliva have been proposed as a diagnostictests for periodontal disease such as intracellular enzymes and alkaline phosphatase is one amongst them. The purpose of this study was to determine the salivary levels of alkaline phosphatase (ALP) activities in patients with periodontal disease in smokers and non-smokers, and to compare them with ALP in healthy individuals. Materials and Methods: In this study, we examined the activities of salivary ALP in 75patients ageing between 20-50 years. The experimental groups consisted of 50 Chronic periodontitis patients( 25 with smoking and 25 without smoking history) and the control group had healthy subjects (25 samples). Unstimulated whole saliva collected from each subject was transferred to auto analyzer to measure the salivary alkaline phosphatase levels. The quantitative analysis of salivary alkaline phosphatase levels of samples obtained from subject groups was done. Results: ALP level were higher in the subjects of chronic periodontitis in smokers habit when compared to non-smokers and healthy individuals Conclusion: Salivary level of Alkaline Phosphatase was significantly elevated in patients with chronic periodontitis in smokers as compared to non-smokers and healthy individuals and can be considered as a biomarker for periodontal disease.