Background: In recent years, worldwide dental malpractice claims have dramatically increased. The purpose of the present study is to analyze periodontal therapy related claims in Israel that led to legal decisions. Methods: This retrospective cohort study includes malpractice claims against dental practitioners related to periodontology between 2005 and 2019. Only closed cases where a final decision was made were included. The chi-square test or Fisher exact test for categorical variables were performed and a p value of 35 years old. Most claims (82.8%) were settled out of court and ended in compromise. Claims concerning the treatment of periodontal disease by periodontists accounted only for 4.5% (23/508) of the cases while 95.5% (485/508) of the claims were for complications secondary to another treatment. Prosthodontic treatment was involved with the highest number 54.5%, followed by dental implants 17.7%, and endodontics 11.6%. The allegations were related to pain and distress (84.8%), aggravation of existent periodontal disease (83.3%), tooth loss (78.1%), and violation of autonomy (47%). Conclusions: The main cause for lawsuits was related to aggravation of periodontal disease during prosthetic or implant therapy and related to suspected faulty or inexistent preoperative diagnosis and planning. Practical implications: Periodontal consultation before dental treatment may reduce malpractice risks, adverse events, and un-necessary changes of treatment plans.