We report on recent measurements of the top quark mass using
tt-bar candidate events selected in \simeq 320 pb-1 of data from the "Run
II" operation period of the Tevatron p anti-p collider. More emphasis is
given on the best single measurement to date (M_top = 173.5 + 3.9_-3.8
GeV/c2), provided by CDF using the "lepton plus jets" channel, where one W
decays to a lepton-neutrino pair and the other into quarks (top quarks decay
to Wb almost 100% of the time).