Techniques for group-based spatial stream assignment signaling in 60 GHz wireless networks are described. According to various such techniques, a 60 GHz-capable transmitting device may be configured to define one or more DL MU-MIMO groups, each of which may comprise one or more respective 60 GHz-capable receiving devices. In various embodiments, the 60 GHz-capable transmitting device may include a DL MU-MIMO group ID within DL MU-MIMO control information in a PHY header of a PPDU in order to indicate that the PPDU is directed to a DL MU-MIMO group corresponding to that DL MU-MIMO group ID. In some embodiments, DL MU-MIMO control information may comprise information specifying spatial stream assignments for the 60 GHz-capable receiving devices of that DL MU-MIMO group. Other embodiments are described and claimed.