In this paper, we report the Bridgman growth of a Er3+/Pr3+ co-doped LiYF4 single crystal with a size of similar to Phi 12 mm x 140 mm and the observation of enhanced 2.7 mu m mid-IR emission of the crystal. The emission characteristics and energy transfer of various parts of crystal upon excitation of a 980 nm laser diode are investigated. Population inversions between I-1(3/2) and I-4(11/2) levels have been achieved. The energy transfer processes are studied based on the I-H model, and the interaction between Er3+ and Pr3+ is confirmed to be electric dipole-dipole. The large energy transfer efficiency of 82.99% and excellent optical transmission indicate that this Er3+/Pr3+ co-doped LiYF4 single crystal has potential applications in 2.7 mu m laser. (C) 2013 Elsevier Ltd. All rights reserved.