ADRIANI, O (reprint author), INFN, SEZ FIRGENZE, I-50125 FLORENCE, ITALY.
The polarization of tau leptons produced in e+e- --> tau+tau- (gamma) is measured using a sample of 8977 tau+tau- pairs collected near the peak of the Z0 resonance. A polarization of -0.132 +/- 0.026 (stat.) +/- 0.021 (syst.) is determined. This corresponds to a ratio of the vector to the axial-vector coupling constants of the tau lepton to the weak neutral current of g(V)tau/g(Aeff)tau = 0.069 +/- 0.017. This leads to a value of the effective sin2theta(w) at the Z0 resonance of sin2theta(eff) = 0.2326 +/- 0.0043.