  The NuTeV experiment at Fermilab presents a determination of the electroweak
mixing angle. High purity, large statistics samples of muon-neutrino and
muon-antineutrino events allow the use of the Paschos-Wolfenstein relation, a
technique which considerably reduces systematic errors associated with charm
production and other sources. Within the Standard Model, this measurement of
sin2thw indirectly determines the W boson mass to a precision comparable to
direct measurements from high energy e+e- and ppbar colliders. NuTeV measures
sin2thw(on-shell)=0.2253+/-0.0019(stat)+/-0.0010(syst), which implies
M_W=80.26+/-0.11 GeV. Outside the Standard Model, this result can be used to
explore the possibility of new physics; in particular, we present limits on
both neutrino oscillations and the presence of extra neutral vector gauge
bosons.
