We measured the B0 lifetime tB0 and the B0-.hivin.B0 oscillation frequency Dmd with a sample of approx. 14,000 exclusively reconstructed B0 -> D*-l+nl signal events, selected from 23 million B.hivin.B pairs recorded at the U(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The decay position of the other B was detd. with the remaining tracks in the event, and its b-quark flavor at the time of decay was detd. with a tagging algorithm that exploits the correlation between the flavor of the b quark and the charges of its decay products. The lifetime and oscillation frequencies were measured simultaneously with an unbinned max.-likelihood fit that uses, for each event, the measured difference in decay times of the two B mesons (Dt), the calcd. uncertainty of Dt, the signal and background probabilities, and b-quark tagging information for the other B. The results are tB0 = (1.523-0.023+0.024 +- 0.022) ps and Dmd = (0.492 +- 0.018 +- 0.013) ps-1. The statistical correlation coeff. between tB0 and Dmd is -0.22. [on SciFinder (R)]