  We discuss the transport of angular momentum induced by tidal effects in a
disk surrounding a star in a pre-main sequence binary system. We consider the
effect of both density and bending waves. Although tidal effects are important
for truncating protostellar disks and for determining their size, it is
unlikely that tidally-induced angular momentum transport plays a dominant role
in the evolution of protostellar disks. Where the disk is magnetized, transport
of angular momentum is probably governed by MHD turbulence. In a non
self-gravitating laminar disk, the amount of transport provided by tidal waves
is probably too small to account for the lifetime of protostellar disks. In
addition, tidal effects tend to be localized in the disk outer regions.
