Recent dietary guidelines emphasize micronutrient sufficiency by giving importance to consumption of whole grains and a variety of fruits and vegetables. The objective of this study was to identify a measure of micronutrient quality of diets in adolescent girls consuming a lacto-vegetarian diet. Data were collected on the nutritional status of 630 schoolgirls (ages 10 to 16 years) from Pune city, India, in a cross-sectional survey during 2006-2007. Dietary intakes were assessed by 24-hour recall on 3 nonconsecutive days. Nutrient intakes were calculated from the Indian nutritive value databases. Micronutrient adequacy was expressed as a ratio of observed intake to reference intake. An Adolescent Micronutrient Quality Index (AMQI) was formulated using the Indian and the recent US dietary guidelines. Fasting blood samples were analyzed for plasma levels of vitamin C, beta carotene, and zinc. The average energy intake of the majority of the girls was below the Indian recommended dietary intakes, whereas micronutrient intakes were 50% to 70% lower than recommended dietary intakes. The mean AMQI score was 41.5+/-9.4. The age of subjects as well as mother's education and occupation were significantly associated with the AMQI. The AMQI was correlated with nutrient intakes and the ratio of observed intake to reference intake (P<0.01) after controlling for energy intake and sociodemographic factors. Higher AMQI scores were associated with higher concentrations of plasma vitamin C (r=0.26), beta carotene (r=0.34), and zinc (r=0.12). The AMQI is a useful measure of the dietary adequacy and micronutrient quality of the diets of adolescent girls consuming lacto-vegetarian diets.