Electronic Journal of Differential Equations, Vol. 2011 (2011), No. 144, pp. 1-7. Title: Existence of three positive solutions for a system of nonlinear third-order ordinary differential equations Author: Nemat Nyamoradi (Razi Univ., Kermanshah, Iran) Abstract: In this work, we use the Leggett-Williams fixed point theorem, we prove the existence of at least three positive solutions of a boundary-value problem for system of third-order ordinary differential equations. Submitted September 11, 2010. Published November 01, 2011. Math Subject Classifications: 34L30, 34B18, 34B27. Key Words: Positive solution; boundary value problem; fixed point theorem.