In this study, an efficient method is presented for solving infinite boundary integro-differential equations (IBI-DE) of the second kind with degenerate kernel in terms of Laguerre polynomials. Properties of these polynomials and operational matrix of integration are first presented. These properties are then used to transform the integral equation to a matrix equation which corresponds to a linear system of algebraic equations with unknown Laguerre coefficients. We prove the convergence analysis of method applied to the solution integro-differential equations. Finally, numerical examples illustrate the efficiency and accuracy of the method.