This paper presents a Discrete-time Model Predictive-based Control strategy for the voltage regulation of an islanded distributed generation (DG) unit. The DG unit includes a voltage source converter (VSC) interfaced to the grid through a switch and a coupling transformer. An RLC branch is also connected in parallel at the point of common coupling (PCC) at the DG-side of the switch. Assuming an open switch and an islanded mode of operation, the Discrete-time Model Predictive-based Controller (DMPC) is adopted to regulate the direct and quadrature (dq) components of the load voltages. The frequency of the load voltage is also regulated in an open loop. In this paper, the design procedure is detailed. Then adopting a laboratory scale setup, the performance of the proposed control strategy is experimentally evaluated. The test results verify the capability of the controller in regulating the load voltages in the nominal plant, and also in the presence of load parameters uncertainties and nonlinear loads.