We have studied t[bar t] production using multijet final states in p[bar p] collisions at a center-of-mass energy of 1.8 TeV, with an integrated luminosity of 110.3 pb[sup [minus]1]. Each of the top quarks with these final states decays exclusively to a bottom quark and a [ital W] boson, with the [ital W] bosons decaying into quark-antiquark pairs. The analysis has been optimized using neural networks to achieve the smallest expected fractional uncertainty on the t[bar t] production cross section, and yields a cross section of 7.1[plus minus]2.8 (stat)[plus minus]1.5 (syst) pb, assuming a top quark mass of 172.1 GeV/c[sup 2]. Combining this result with previous DO/ measurements, where one or both of the [ital W] bosons decay leptonically, gives a t[bar t] production cross section of 5.9[plus minus]1.2 (stat)[plus minus]1.1 (syst)thinsppb. [copyright] [ital 1999] [ital The American Physical Society]