The D0 Collaboration has performed a measurement of the top quark mass mt based on six candidate events for the process tt¯→bW+b¯W−, where the W bosons decay to eν or μν. This sample was collected during an exposure of the D0 detector to an integrated luminosity of 125pb−1 of s=1.8TeVpp¯ collisions. We obtain mt=168.4±12.3(stat)±3.6(syst)GeV/c2, consistent with the measurement obtained using single-lepton events. Combination of the single-lepton and dilepton results yields mt=172.0±7.5GeV/c2.Received 16 June 1997DOI:https://doi.org/10.1103/PhysRevLett.80.2063©1998 American Physical Society