The temperature dependence of vibrational relaxation rates of N-2(v=1) by O-2 in liquid N-2 has been studied at several temperatures along the coexistence curve between 80 and 120 K. A small amount of CO was added to the N-2-O-2 mixture as a pump and a probe. A CO laser was used to excite CO in solution and its fluorescence was monitored to obtain the rate of vibrational energy transfer. The liquid-phase rate constants k(l) were compared with the gas-phase constants k(g) at the same temperatures and found to be essentially equal. This result is in reasonable agreement with the predictions of the isolated binary collision model.