  In this paper we review the present status of observations of the Big Bang
elements D, 3He, 4He and 7Li and of their extrapolation to the primordial
values. It is shown that, within the errors, the abundances are consistent with
the predictions of the standard Big Bang nucleosynthesis for 1 < eta_10 < 6,
which corresponds to 0.004 < Omega_b h_{0}^2 < 0.02$. Narrower consistencies in
eta_{10} are still possible at about 1.7 or about 4, but in this case some of
the observations of D and 4He should be incorrect. Finally, it is noted that
"extragalactic" Li may have already been detected in a star possibly accreted
by the Galaxy.
