This study aims to investigate the effect of Bluetooth on WLAN 802.11 performance. In contrast to other studies, we distinguish bluetooth into two mechanisms, namely Asynchronous Connectionless (ACL) and Synchronous Connection-Oriented (SCO). Various scenarios (with range variation between the sender node and the access point (AP) and also the presence of ACL or SCO transmission as interference) was designed to conduct experiment. In general, experiment was conducted with two nodes that act as sender and receiver node that connected through internet. In addition, to determine the effect of bluetooth on WLAN performance we use several test parameters, which are received signal strength indication (RSSI), signal to noise ratio (SNR), upstream and downstream, jitter, and packet loss rate (PLR). The study revealed the both ACL and SCO did not significantly affect WLAN performance, because they can only reduce the performance based on certain parameters and scenarios. But when they were compared, SCO has worst effect on WLAN performance, particularly on upstream, jitter, and PLR.