The CDF collaboration has analyzed ~200 pb-1 of Tevatron Run
II data taken between February 2002 and September 2003 to measure the
W boson mass. With a sample of 63964 W --> e nu decays and 51128 W
--> mu nu decays, we measure M_W = 80413 +/- 34(stat) +/- 34(syst;)
MeV/c2. The total measurement uncertainty of 48 MeV/c2 makes this result
the most precise single measurement of the W boson mass to date.