  We discuss the CP-violating dimuon charge asymmetry of events p p-bar ---> B
B-bar X ---> mu mu X in the Standard Model. Our conclusion is that the
asymmetry is larger than previously expected and may reach a few percent for
the (B_d^0, B-bar_d^0) system. The analysis is also extended to the Two Higgs
Doublet Model (Model II).
