Background: Healthy conditions can affect human behavior, one of which is by implementing clean and healthy living behavior (PHBS) in maintaining dental and oral health. PHBS can be influenced by several factors, one of which is knowledge. According to several studies, if a person's knowledge is good, then PHBS will also be good, and will have a good impact on his life. In their growth and development, adolescents often experience health problems, especially in the gingiva. One of the problems that occur is supported by lifestyle, food and hormonal factors. Objective: This research was conducted to find out how the relationship between knowledge about dental and oral health and gingivitis in adolescents in West Ciberang Village Rt/10 Rw/03 Pandeglang Regency, Banten. Methods: This study uses a type of observation with a Spearman range design with a research sample of 30 teenagers. Data collection techniques were done by filling out a questionnaire and calculating the gingivitis index. Data analysis was carried out using the Spearman range test. Result: The results of the Spearmane Range Test showed an asymp sig value of 0.004 < 0.005, Conclusion: so it can be concluded that there is a relationship between knowledge about oral health and gingivitis in adolescents in Kampung Cilanggar Barat Rt/10 Rw/03 Pandeglang Regency, Banten.