Smoking has its effects on the periodontium, which is reflected by morphologic and histologic changes in the gingiva. Gingival thickness is one among the factors, which has become a subject of considerable interest in periodontics both from the epidemiological and therapeutic point of view. By taking gingival thickness into consideration during treatment planning, more appropriate strategies for periodontal management may be developed, resulting in more predictable treatment outcomes. The purpose of the study was to estimate the gingival thickness in different regions of the mouth in smokers and non-smokers. The study group included 40 age-matched smokers and non-smokers with and without periodontitis. Gingival thickness assessment was done on 6 index teeth; 6 sites on each tooth by transgingival probing using 15 sizes endodontic reamer and thickness was measured using vernier caliper. A statistically significant difference in gingival thickness was observed in different sextants of mouth in smokers and non-smokers.