The main purpose of this paper is to present a fuzzy extension for the classical sheet pile problems. The governing differential equations are derived for the behavior of steel sheet piles with fuzzily specified mediums: the earth pressure and the flexural rigidity of the sheet piles. The earth pressure is taken to be in accordance with the Rankine distribution defined the fuzzy variables. The vertex method is used to evaluate the fuzzy functions. The Runge-Kutta method and bisection method are used to solve the differential equations and to determine the unknown parameter, respectively. The membership functions of the deflection, the angle of rotation and the moment along the axis of the steel sheet piles are calculated. The index of fuzziness to quantitatively describe the propagation of fuzziness in the behavior is defined. The membership functions of the anchor load are calculated for the sheet piles with fuzzy earth pressure. It is expected that the designer, using the index of fuzziness, can provide suitable margins of safety in regions of maximum fuzziness.