  WThe current status of big bang nucleosynthesis is reviewed with an emphasis
on the comparison between the observational determination of the light element
abundances of \D, \he3, \he4 and \li7 and the predictions from theory. In
particular, we present new analyses for \he4 and \li7. Implications for physics
beyond the standard model are also discussed. Limits on the effective number of
neutrino flavors are also updated.
