Anaemia is one leading cause of morbidity among adolescent girls. Prevention, early detection, and treatment can break the intergeneration cycle of malnutrition. The aim of the study was to estimate the prevalence of anaemia and assess its sociodemographic determinants and understand its association with the dietary pattern of rural adolescent girls. A cross-sectional study was conducted among 350 adolescent girls studying in the school of Kalgatigi Taluk, Dharwad district. The school girls were interviewed using a predesigned structured questionnaire by interview method. A food frequency questionnaire was used to assess the dietary pattern. Haemoglobin levels were estimated using Sahli's method. Data were entered in Microsoft Excel and analysed using SPSS version 19 and the Chi-square test was applied to study the significance. Rural adolescent school girls between the age group of 13-16 years were included. The prevalence of anaemia among them was found to be 47.4% and was significantly associated with the educational status of the mother, their socioeconomic status (SES), and type of diet. Vegetarian girls had a higher prevalence of anaemia. The frequency of meat and egg consumption was significantly associated with anaemia. The prevalence of anaemia was higher in thin and severely thin girls based on WHO-BMI. Anaemia in rural adolescent girls is of high burden and public health importance with a prevalence of 47.4% and significant association with dietary habits, SES, and BMI.