Data taken by the Mark II detector at the PEP storage ring was used to measure the rate of dilepton production in multihadronic events produced by e+e- annihilation at √s=29 GeV. We determine the probability that a hadron initially containing a b (b̄) quark decays to a positive (negative) lepton to be 0.17-0.08+0.15, with 90% confidence level limits of 0.06 and 0.38. © 1990.