Aim: The aim of this study was to evaluate the efficacy of a locally delivered 2% minocycline as an adjunct to scaling and root planing plus oral hygiene measures in treating chronic periodontitis smoker patients. Materials and Methods: This was a randomized controlled trial using a split-mouth study design. Twenty pairs of sites in twenty smoker patients with similar deep probing depths were randomly allocated to test and control groups. The test sites received minocycline after root debridement. The clinical parameters included the plaque index, probing pocket depths, attachment levels, and bleeding upon probing. They were evaluated at the baseline, and after 3 and 6 months. Results: Both the test and control sites showed statistically significant improvements in the clinical periodontal parameters over the baseline measurements during the study period (P<.05). In follow-up, the intervals sites that received minocycline showed more favorable results manifested by probing depth reduction. This improvement was constant at 3 and 6 months and the difference between the two groups was statistically significant (P<.05). Conclusion: The study results show that patient motivation to maintain meticulous oral hygiene self-care with adjunctive professional dental care using local delivery 2% minocycline can significantly enhance treatment outcome of deep periodontal pockets in chronic periodontitis smoker patients. Keywords: Minocycline; Local delivery; Smoking; Chronic periodontitis