  We report on a recent calculation of the electroweak O(\alpha^3\alpha_s)
corrections to 3-jet production and related event-shape observables at e+e-
colliders. The calculation properly accounts for the experimental photon
isolation criteria and for the corrections to the total hadronic cross section.
Corrections to the normalised event-shape distributions, which are exemplarily
discussed here for the thrust distribution at LEP and linear-collider energies,
turn out to be at the few-per-cent level and show remnants of the radiative
return to the Z pole even after inclusion of appropriate cuts.
