  Deuteron and anti-deuteron production in Z decays has been observed in the
ALEPH experiment at LEP. The production rate of anti-deuterons is measured to
be 5.9+-1.8+-0.5 10^-6 per hadronic Z decay in the anti-deuteron momentum range
0.62 to 1.03 GeV/c. The coalescence parameter B_2, which characterizes the
likelihood of anti-deuteron production, is measured to be 0.0033+-0.0013 GeV^2
in Z dedays. These measurements indicate that the production of anti-deuterons
is suppressed in e+e- collisions compared to pp and photoproduction collisions.
