Nutritional status during adolescence plays an important role in human lifecycle. Malnutrition among adolescents is not only an important health problem but also an economic development issue in Iran and other developing countries. High incidence of nutritional deficiencies and poor eating habits during adolescence may lead to consequences in later years including osteoporosis, obesity, hyperlipidemia, sexual maturation delay and final adult height. This study has been intended to investigate nutritional status and its determinants among adolescent girls in Semnan, Iran. In a cross-sectional study design and two stage cluster sampling methods, anthropometric measurements were performed. Data on socio-demographic, individual and nutritional factors was collected by administered questionnaires from adolescent girls. Logistic regression analyses were performed to identify which factors have the strongest influence on the manifestation of malnutrition.