Abstract: The present study assesses the frequency of underweight in primary school children from families of high socioeconomic status in Dera Ismail Khan City, Pakistan. It included 322 children, 221 (68.63%) boys and 101 (31.37%) girls. The schools such as The Qurtruba, The City and The Educators were selected as they are the only institutions that cater wards of high socio economic group in Dera Ismail Khan. They were living in healthy environments, have excellent nutrition and easy access to health facilities. Thorough medical examination excluded those suffering from chronic health ailments. Height and weight of each child was taken. BMI was calculated according to the Quatelet’s Index and body mass status according to WHO S′ criteria. The BMI-for-age percentile was derived by putting BMI values on gender specific CDC S′ growth charts 2-20 years. Children falling below 5th percentile were declared as under weight and those >95th percentile as obese. Frequency of under weight in primary school children was found 5.59% (in sample): 4.03% for boys and 1.55% for girls. Boys were more than two times under weight than girls. This may be due to absence of gender discrimination; easy access of girls to kitchen and food stored in the house. It also reflects the changing attitude of these families about the status of women; improvement in the level of education, economics and knowledge about nutrition.