  A fourth generation of quarks, if it exist, may provide sufficient CP
violation for the baryon asymmetry of the Universe. We estimate the neutron
electric dipole moment in the presence of a fourth generation, and find it
would be dominated by the strange quark chromoelectric dipole moment, assuming
it does not get wiped out by a Peccei-Quinn symmetry. Both the three
electroweak loop and the two-loop electroweak/one-loop gluonic contributions
are considered. With m_{b'}, m_{t'} at 500 GeV or so that can be covered at the
LHC, and with a Jarlskog CPV factor that is consistent with hints of New
Physics in b to s transitions, the neutron EDM is found around 10^{-31}e cm,
still far below the 10^{-28}e cm reach of the new experiments being planned or
under construction.
