Penelitian bertujuan untuk mengetahui pengaruh anemia dan Indeks Massa Tubuh (IMT) Terhadap siklus menstruasi remaja putri. Jenis penelitian ini adalah analitik observasional dengan rancangan penelitian kohort. Penelitian ini menggunakan data primer. Pengumpulan data awal meliputi pengukuran berat badan dan tinggi badan, pengambilan sampel darah dan kuesioner. Untuk penentuan anemia dilakukan dengan pemeriksaan sampel darah dengan Hb Sahli. Penentuan siklus menstruasi dengan pengisian kuesioner tentang menstruasi selama 3 bulan. Analisis data menggunakan program komputer dengan derajat kepercayaan 95%. Analisis bivariat menggunakan chi square dengan α 0,05. Regresi logistik ganda digunakan untuk melakukan analisis multivariat. Hasil Penelitian menunjukan 15 % remaja putri mengalami anemia,48,3% indeks massa tubuh tidak normal dan 46,7 % siklus menstruasi tidak normal. Tidak terdapat pengaruh anemia dan indeks massa tubuh terhadap menstruasi remaja putri. Berdasarkan hasil penelitian maka remaja putri perlu melakukan pemeriksaan kadar Hb secar rutin untuk mencegah anemia secara dini dan mengkonsumsi makanan bergizi yang sangat dibutuhkan pada saat menstruasi.ABSTRACTThe prevalence of anemia in the world is 46% according to WHO and 68% of women based on Riskesdas experience irregular menstruation. Menstrual cycle disorders have an increased risk of cancer and cardiovascular disease. Anemia and nutritional status is one of the factors that can affect menstruation. The study was to determine the effect of anemia and Body Mass Index (BMI) on the menstrual cycle of young women. This type of research is observational analytic with a cohort study design. This study uses primary data. Initial data collection included measurements of body weight and height, blood sampling and questionnaires. The determination of anemia was carried out by examining blood samples with Hb Sahli. Determination of the menstrual cycle by filling out a questionnaire about menstruation for 3 months. Data analysis using a computer program with a 95% confidence level. Bivariate analysis using chi square with α 0.05. Multiple logistic regression is used to conduct multivariate analysis. The results showed 15% of female adolescents had anemia, 48.3% of body mass index was abnormal and 46.7% of menstrual cycle was abnormal. There is no influence of anemia and body mass index on menstruation for young women. Based on the results of the study, young women need to check Hb levels regularly to prevent anemia early and consume nutritious foods that are needed during menstruation.