With the introduction of Actisite (tetracycline hydrochloride) periodontal fiber therapy, controlled drug delivery of tetracycline into the periodontal pocket has become a clinical reality. An important factor in the success of this treatment option is the selection of suitable candidates according to specific patient selection criteria proposed by the author in this article. Case reports describing periodontal tetracycline fiber therapy, used adjunctively with conventional mechanical therapy and oral hygiene, document the reductions in pocket depth and bleeding upon probing over a six-month follow-up period, suggesting the value of this therapy in maintaining the periodontal health of patients who meet the selection criteria.