  We present a measurement of the ttbar cross section using high-multiplicity
jet events produced in ppbar collisions at sqrt{s}=1.96 TeV. These data were
recorded at the Fermilab Tevatron collider with the D0 detector. Events with at
least six jets, two of them identified as b jets, were selected from a 1 fb-1
data set. The measured cross section, assuming a top quark mass of 175 GeV/c^2,
is 6.9 \pm 2.0 pb, in agreement with theoretical expectations.
