The foot builds the basis of human anatomy and its locomotor system. It acts statically and dynamically while, depending on the dynamics of the human body. Throughout human evolution, the foot underwent anatomical changes adapting to the environment and lifestyle. Modern man adopted a sedentary lifestyle to a large extent, which impairs his motor skills and health. Flat foot (pes planus) is the most common deformity of the lower extremities today. It is caused by the loosening of the arch, weakening of the muscles and the bone-ligament complex. It occurs regardless of age, but mostly in children who are in the phase of accelerated growth and development. The causes of foot deformities can be hereditary circumstances, body constitution and too little movement. If the arch of the foot is completely lowered, it is called a flat foot. The status of the feet in adults and children can be diagnosed with various instruments and methods. Many studies deal with the subject of flat foot in children with the aim of linking the causes of the deformity. This paper aims to investigate possible influence of gender and body weight on flat foot in preschool children. The research was conducted in a preschool institucion in the city of Zagreb. It includes 64 respondents, aged 6 to 7 years (30 boys and 34 girls). Children's footprints were obtained by a podographer, after which they were qualified by Mayer's method. Anthropometric measurements were performed by measuring body weight and body height within the preschool facilities. The data are presented in graphs and statistically processed with the Chi-square test. The results of the research proved the thesis that there is no influence of gender on flat foot in preschool children, nor that there is an influence of body weight. Out of 64 samples, Out of 64 samples, 37% showed flat foot deformity (47% of boys and 27% of girls). The body mass index in flat foot showed an average of 16.32 in girls and 15.42 in boys. A box plot graph shows the dispersion of the entered data, for both genders together and individually for each. The Chi-square test confirmed the thesis that there is no significant statistical difference between the gender and foot status, and this thesis research by Fung, Dias Ismiarto and Mayasari (2017) and research by Kahile, Deshmukh, Muley and Suryawanshi (2020). The thesis that there is no significant statistical difference between the nutritional status of the children and the status of the feet was also confirmed .