  Lattice QCD has always played a relevant role in the studies of flavor
physics and, in particular, in the Unitarity Triangle (UT) analysis. Before the
starting of the B factories, this analysis relied on the results of lattice QCD
simulations to relate the experimental determinations of semileptonic B decays,
K-Kbar and B_{d,s}-B_{d,s}bar mixing to the CKM parameters. In the last years
much more information has been obtained from the direct determination of the UT
angles from non-leptonic B decays. In this talk, after a presentation of recent
averages of lattice QCD results, we compare the outcome of the "classical" UT
analysis (UTlattice) with the analysis based on the angles determinations
(UTangles). We discuss the role of the different determinations of Vub, and
show that current data do not favour the value measured in inclusive decays.
Finally we show that the recent measurement of Delta ms, combined with Delta md
and epsilonK, allows a quite accurate extraction of the values of the hadronic
parameters, BK, fBs*sqrt(B_Bs) and xi. These values, obtained "experimentally"
by assuming the validity of the Standard Model, are compared with the
theoretical predictions from lattice QCD.
