The Tevatron collider at Fermilab provides a very rich
environment for the study of b-hadrons. Both the D0 and CDF experiments
have collected a sample of about 1 fb-1. We report results on three
topi+cs: b-hadron lifetimes, polarization amplitudes and the decay width
difference in B0(s) --> J/psi phi, and B0(s) mixing.