•Data on mid-upper arm circumference, including centiles and cutoffs for over- and undernutrition for Asian Indian children 5 to 17 y of age are presented for the first time.•Multicentric data and standardized methodology are used throughout the study.•These ethnic-specific data may be used for quick assessment of nutritional status in children with chronic disorders such as cancer. Malnutrition is common in developing countries and is not restricted to young children. It has been suggested that measuring mid-upper arm circumference (MUAC) is an easy, accurate, and low-cost method of identifying malnutrition in the early stages. The aims of this study were to construct age- and sex-specific MUAC reference centiles, and to define and validate cutoffs for assessment of under- and overnutrition in Indian children 5 to 17 y of age. This was a cross-sectional, multicentric, observational study conducted in seven schools in seven states from June 2018 to November 2019. The study included 6680 healthy 5- to17-y-old children. MUAC was measured using non-stretch tapes (UNICEF). Sex-specific MUAC percentiles were computed for age and height. Cutoffs for MUAC z-scores for thinness and overnutrition were defined and validated for healthy school children (n = 726) and children with cancer (n = 500). Reference centiles for MUAC for age (and height) for boys and girls are presented. Cutoffs defined for thinness and for obesity were –0.7 and +1.5 z-score, respectively (corresponding to 25th and 95th percentiles of the MUAC for age/height). For ease of use, rounded cutoffs for thinness were 16 and 18.5 cm from 5 to 9 and 10 to 14 y of age, respectively, in both sexes, and a cutoff of 22 cm in boys and 20 cm in girl from 15 to 17 y of age. For obesity, 20 and 25.5 cm from 5 to 9 and 10 to 14 y of age, respectively, in both girls and boys and a rounded cutoff of 29 cm in boys and 27 cm in girls from 15 to17 y are proposed. We presented MUAC percentiles and cutoffs for screening for thinness and overnutrition in Indian children from 5 to 17 y of age. These data may also be used in children with cancer and other chronic disorders with growth failure.