  We present the first direct experimental bound on the total decay width of
the top quark using 955pb^-1 of the Tevatron's ppbar collisions recorded by the
Collider Detector at Fermilab. We identify 253 top-antitop pair candidate
events. The distribution of reconstructed top quark mass from these events is
fitted to templates representing different values of the top quark width. Using
a confidence interval based on likelihood ratio ordering, we extract an upper
limit at 95% C.L. of Gamma_t <13.1 GeV for an assumed top quark mass of 175
GeV/c^2.
