Adolescence is a transition period from childhood to adulthood. In Indonesia, around 90% of women menstruate every month, but the onset of menstruation can cause anemia for teenagers who experience it. This is caused by several things, of course because there is irregular bleeding, this is caused by the teenager’s age itself. , parental factors, including education and work, each person’s food intake/nutritional status, and also the menstrual cycle/length of menstruation experienced each month. This research aims to determine the factors associated with the occurrence of anemia in adolescent girls at Umi Kulsum Banjaran Middle School in 2022. The research method used is a quantitative analytical approach research design with a cross sectional research design. The research population was all 120 female students and the sample used was 55 people using the random sampling technique. Data collection was carried out by means of interviews and direct examination of respondents. Data analysis went through three stages, univariate (frequency distribution), bivariate (chi square) and multivariate analysis (Logistic Regression). The results of the research show that there are factors that are associated with the incidence of anemia in adolescent girls, including age, nutritional status and length of menstruation with a p-value <0.05. It is recommended that students increase their knowledge about reproductive health, especially those related to enstruation, educational institutions can optimize education about adolescent reproductive health by collaborating with health workers in the surrounding environment.