  We present a measurement of the KL lifetime using the KLOE detector. From a
sample of 4 x 10^8 KS KL pairs following the reaction e+ e- -> phi -> KS KL we
select 15 x 10^6 KL -> p0 p0 p0 decays tagged by KS -> pi+ pi- events. From a
fit of the proper time distribution we find tau_L = (50.92 +- 0.17{stat} +-
0.25{syst})$ ns. This is the most precise measurement of the KL lifetime
performed to date.
