Periodontitis is an inflammatory disease of the supporting tissues of the teeth caused by groups of specific microorganisms. The concept that localized problem sites may be treated by local drug delivery appears attractive as the antimicrobial agent is delivered within periodontal pockets and the therapy is targeted on specific pathogenic microorganisms. Local delivery of antimicrobial agents using controlled release systems should be considered as adjunctive to mechanical debridement for the treatment of localized forms of periodontal destruction. Local delivery of in situ gelling system to periodontal pockets has the benefit of putting more drugs at target site while minimizing exposure of the total body to the drug. In situ gelling system helps in maintaining effective levels of drug in gingival cervicular fluid to produce desirable clinical effects. In situ gel for controlled drug delivery system of periodontal pocket has received greater interest and appears to hold some promise in periodontal therapy. They are designed to release drug slowly with more prolonged drug availability and sustained drug action. Controlled release systems offer an advantage of decrease in frequency of administration, improving patient compliance. The dose of the drug can also be decreased and hence, the toxicity when compared to conventional therapy. In controlled drug delivery, the drug is released over an extended period of time by zero order kinetics and hence constant plasma drug concentration can be achieved. Key words: Periodontitis, Periodontal pocket, In situ gel, Controlled drug delivery