Variational and Topological Methods: Theory, Applications, Numerical Simulations, and Open Problems. Electron. J. Diff. Eqns., Conference 21 (2014), pp. pp. 23-30. Title: Existence of positive solutions for a superlinear elliptic system with Neumann boundary condition Authors: Juan C. Cardeno (Univ. de Ibague, Tolima, Colombia) Alfonso Castro (Harvey Mudd College, Claremont, CA, USA) Abstract: We prove the existence of a positive solution for a class of nonlinear elliptic systems with Neumann boundary conditions. The proof combines extensive use of a priori estimates for elliptic problems with Neumann boundary condition and Krasnoselskii's compression-expansion theorem. Published February 10, 2014. Math Subject Classifications: 35J20, 35J60, 35B38. Key Words: Semilinear elliptic system; a priori estimates; ordered Banach space; contraction-expansion operator; Neumann boundary condition.