We report on a measurement of σ(pp¯→W+X)B(W→τν) in pp¯ collisions at s=1.8TeV at the Fermilab Tevatron. The measurement is based on an integrated luminosity (lum) of 18pb−1 of data collected with the D0 detector during 1994–1995. We find that σ(pp¯→W+X)B(W→τν)=2.22±0.09(stat)±0.10(syst)±0.10(lum)nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, gτW/geW, be unity. We find gτW/geW=0.980±0.031, in agreement with lepton universality.Received 28 December 1999DOI:https://doi.org/10.1103/PhysRevLett.84.5710©2000 American Physical Society