  The properties of the recently discovered Ultra-Compact Dwarf Galaxies (UCDs)
show that their internal acceleration of gravity is everywhere above a0, the
MOdified Newtonian Dynamics (MOND) constant of gravity. MOND therefore makes
the strong prediction that no mass discrepancy should be observed for this
class of objects. This is confirmed by the few UCDs for which virial masses
were derived. We argue that UCD galaxies represent a suitable test-bench for
the theory, in the sense that even a single UCD galaxy showing evidence for
dark matter would seriously question the validity of MOND.
