Background:An assessment of the process of changes in growth indices of children basaed on gender differences not only does provide the required information of the child's growth pattern, rather it also prepares the ground for a dynamic comparison of gender differences as a sensitive indicator of gender discrimination. The current research has been designed and implemented for depicting the growth patterns of children under two years old.Methods:Through a secondary analysis based study, the health files of 1336 children under 2 years old (700 boys and 636 girls) in the maternal and child health care system in Kohkiluyeh and Boyer Ahmad Province in 2017 were analyzed in terms of the nutritional status and in view of underweight and skinniness (wasting) and stunting (stunted growth) based on WHO standardization indicators.Results:The average difference of weight, height and head circumference of male and female children in the early days of their birth were respectively 67 g, 0.36 and 0.37 cm. Although z standardized score charts for average weight, height, and head circumference did not show a significant difference in the course of two-year period among boys and girls, the percentage ratio of boys as compared to girls in low weight at birth, six months, one year and two years old are respectively 0.98, 1.7, 12.4 and 1.5 for weight loss index 2.4, 1.73, 2.9 and 1.9, and for the short height (stunted growth) indexes 1.3, 1.48, 1.4 and 1.6, and for the head circumference index 0.48, 2.27, 1.56 and 1.6, and these indicate a constant gap between the boys with low weight, skinny and low head circumference measure and girls.Discussion and conclusion:In spite of the closeness of weight, height and head circumference differences in newborn girls and boys, their growth difference over the two-years period was associated with boys' superiority. In other words, boys had a more desirable growth trend than girls in terms of averaging indices. On the other hand, the percentage of male children with low weight, wasting and short height in the whole course of the study was more than female subjects. The research findings not only lay an emphasis on the gap between boys and girls in view of the studied indices, but also underlines the fact that in epidemiological studies, comparisons of averages are not an appropriate approach for comparing populations, and this in turn reveals the urgent need to pay more attention to frequency-based indicators. The recent attitude shift that has occurred among Iranian familes in terms of giving much care to girls as compared to boys against the previous inverted approach seems to be one of the most important justifications for this difference in growth trend.