The main objective of the MAC protocol in IEEE 802.11 standard is to access and control the shared limited bandwidth medium efficiently and fairly among all nodes. A maximum throughput is difficult to achieve due to the limited bandwidth of the wireless ad hoc networks, packet overhead, and hidden and the exposed terminal problems. The use of NACK control packets instead of ACKs can minimize network congestion and packet collisions. In this paper, we implement and investigate the use of NACKs over the RTS/CTS handshake mechanism for single-hop wireless ad-hoc networks. The results show a significant performance improvement of throughput, and system delay for various network sizes and BERs.