Flat foot in children is a common deformation, which appears during the first years of life. It requires a rigorous evaluation to rule out congenital or neurological abnormality. It is characterized by a decrease of the plantar concavity indeed collapse of the foot, often associated with other morphostatic deformations. The aim of this study is to find a correlation between the essential flat foot in children and lower limb disorders torsional. It is a cross-sectional descriptive study, recruiting 110 children (220 feet) aged between 3 and 6 years old. Each child was given an assessment of the morphology of the foot (Contact Index II…) and lower limb rotational profile (intoeing and femoral antétorsion and tibal torsion). Among 110 children, 21 (19.1%) have bilateral flat feet and 7 (6.4%) have unilateral flat feet, associated with an average value of Contact Index II equal to 0.921; the minimum value is 0.880 and the maximum value is 1.17. All children with flat feet have excessive femoral antétorsion; 45 (92%) are associated with a hip intoeing and 38 (80%) present an insufficient external tibial torsion. The analysis of multiple regression shows a significantly elevated correlation among the flat foot and excessive internal rotation of the hip (F = 70.36, r = 0.77, P < 0.001), excessive femoral antetorsion (F = 54.78, r = 0.73, P < 0.001) and insufficient external tibial torsion (F = 7.79, r = 0.37, P < 0.001).