B Lifetimes and Mixing at the Tevatron
  We present recent results on b-hadron lifetimes and mixing obtained from the analysis of the data collected at the Tevatron Collider by the CDF and D0 Collaborations in the period 2002 - 2004. Many lifetime measurements have been updated since the Summer 2004 conferences, sometimes improving significantly the accuracy. Likewise the measurement of the $B_d$ oscillation frequency has been updated. New limits on the $B_s$ oscillation frequency have been determined using for the first time Run II data. 
Franco Bedeschi