Electronic Journal of Differential Equations, Vol. 2013 (2013), No. 125, pp. 1-16. Title: Existence of multiple solutions for a mixed boundary-value problem Authors: Shapour Heidarkhani (Razi Univ., Tehran, Iran) Ghasem Alizadeh Afrouzi (Univ. of Mazandaran, Babolsar, Iran) Armin Hadjian (Univ. of Mazandaran, Babolsar, Iran) Abstract: Using three critical points theorems, we prove the existence of at least three solutions for a second-order mixed boundary-value problem. Submitted October 31, 2012. Published May 21, 2013. Math Subject Classifications: 34B15, 35B38, 58E05. Key Words: Mixed boundary value problem; critical points; variational methods.