The recently developed IEEE 802.11ad (WiGig) standard offers multi-Gbps connectivity for consumer wireless local area networks and operates in the millimeter wave frequency band (around 60 GHz). It supports two different contention-based channel access mechanisms, namely distributed coordination function, which offers fair service for every station, and the enhanced distributed channel Access (EDCA) for offering service differentiation among the stations. In this paper, we study the throughput performance of the IEEE 802.11ad EDCA mechanism under saturated traffic conditions using both analytical and simulation models. A novel five-dimensional Markov chain developed is used for analytically modeling the throughput behavior of the IEEE 802.11ad EDCA in the presence of virtual antenna sectors, high-gain directional beamforming, and presence of contention and contention-free access periods. Using this developed analytical model, the effect of the number of sectors, number of stations, arbitration inter-frame space, packet length, and minimum contention window size on the throughput of the four different access or service categories present in the EDCA under saturated traffic conditions, is investigated. When compared with the simulation outcomes, the proposed analytical model accurately analyzes the network performance by achieving less than 4% error. © 1967-2012 IEEE.