A precise predictability of the results of a disease is profound and crucial for proper treatment planning. Since the understanding of periodontal disease has progressed to include the influence of risk factors, assigning a prognosis has become more perplexing to the clinician. Various factors that influence the overall and individual tooth prognosis have been enumerated, as well as the classification systems required to assign a prognosis has also been included. An experienced clinician should analyse all these factors, along with the patients attitude towards dental therapy, prior to arriving at a judgement for a single tooth or teeth. With newer trends in treatment modalities, patients can seek better options for treatment, thus improving the long term prognosis. This book highlights a detailed overview related to devising a periodontal prognosis.