We have obtained an accurate estimate of the absolute I magnitude of the Tip of the Red Giant Branch ( M _ { I } ^ { TRGB } ) for the globular cluster \omega Centauri , based ( a ) on the largest photometric database ever assembled for a globular , by Pancino et al .
( 2000 ) , and ( b ) on a direct distance estimate for \omega Centauri , recently obtained by Thompson et al .
( 2001 ) from a detached eclipsing binary .
The derived value M _ { I } ^ { TRGB } = -4.04 \pm 0.12 provides , at present , the most accurate empirical zero-point for the calibration of the M _ { I } ^ { TRGB } – [ Fe/H ] relation , at [ Fe/H ] \sim - 1.7 .