Anaemia is a major cause of concern during adolescence particularly among the persons of tribal origin. The objective of the study was to determine the pattern of anaemia, determinants and coverage of the weekly iron and folic acid supplementation (WIFS) programme among adolescent girls in a tribal area. A cross sectional study was conducted among 196 adolescent girls at a primary health care centre in tribal area of Kerala. Every alternate adolescent girl attending the centre was chosen over a period of three months. Assent and informed consent from accompanying parents was obtained. Haemoglobin was estimated by Sahli’s method and peripheral smear prepared. Three fourths of the adolescent girls had iron deficiency anaemia; of which 48.64% had moderate anaemia 5.40% had severe anaemia and 1.6% had sickle cell anaemia. Adolescents belonging to Paniya tribe and those not consuming Iron and folic acid tablets under WIFS programme were three times (OR 2.95 95% CI 1.38,6.28) and two times (OR 2.5 95% CI 1.24, 5.11) respectively were more likely to be anaemic. Most (80%) of the anaemic girls were unaware about WIFS scheme and the intake of the iron supplementation was significantly higher in school going girls. Strengthening the WIFS scheme by targeting the vulnerable adolescent girls of Paniya tribe and out of school girls are of extreme importance in tackling the problem of anaemia among tribal adolescent girls.