  We employ an effective Lagrangian approach and use LEP data to place severe
bounds on universality violations of the couplings of $\nu_e$, $\nu_\mu$, and
$\nu_\tau$ to the $Z$ boson. Our results justify the assumption of universality
in these couplings that is usually made, as for example in the analysis of
solar neutrinos detected at SNO.
