Airfoils operating under low Reynolds number conditions are susceptible to laminar separation, which can cause significant performance losses. The flow field around a two-dimensional, slightly modified NACA 643 - 618 airfoil was investigated experimentally for a wide range of angles of attack (between -12° and 21°). At chord Reynolds numbers of Re = 64, 200 and Re = 137, 000 and at moderate angles of attack, the airfoil suffers severe performance losses due to large regions of laminar separation on its suction side. Open-and closed-loop flow control strategies were employed to eliminate or at least to significantly reduce laminar separation. When successful, the control resulted in a significant lift recovery and drag reduction. Closed-loop control was found to be equally effective as an optimized open-loop control. The main advantage of the proposed easy-to-implement feedback controller is that it automatically adjusts the unsteady actuation to changing free-stream conditions.