This poster presents the development of an iterative Poisson solver for the Xcompact3d framework. The development of x3d2, the next generation of the Xcompact3d solver targeting massively parallel multicore and GPU-based architectures, has included implementing distributed tridiagonal solvers. These distributed tridiagonal solvers enable a 3-D parallel decomposition of the bulk of the computation, exposing greater opportunity for parallelism than the currently used 2-D decomposition. The present FFT-based spectral Poisson solver however prevents this. In this work an iterative Poisson solver is developed for the high-order schemes employed by Xcompact3d/x3d2 and is used to demonstrate solution of the Navier-Stokes equations using a 3-D parallel decomposition for the first time in the Xcompact3d framework.