High quality Er3+/Nd3+:LiYF4 single crystals were grown by a Bridgman method. Their spectroscopic properties were studied to understand the Nd3+ concentration effect upon excitation of an 800 nm laser diode. The intensest 2.7 mu m emission was observed in the LiYF4 crystal codoped with 0.99 mol% Er3+ and 0.62 mol% Nd3+. Meanwhile, the emission intensity for the green up-conversion and 1.5 mu m downconversion of Er3+ decreased with increasing of the Nd3+ concentration. The modified Inokuti-Hirayama model was used to analyze the decay curves of the 1.06 (Nd3+) and 1.5 (Er3+) gm emissions. The results indicated that the energy transfer process (Er3+:I-4(13/2) + Nd3+:I-4(9/2) -> Er3+:I-4(15/2) + Nd3+:I-4(15/2)) is mainly due to the electric dipole-dipole interaction. The energy transfer efficiencies between Nd3+ and Er3+ ions were calculated. All results suggested that the Er3+/Nd3+:LiYF4 single crystals may have potential applications in mid-infrared lasers. (C) 2014 Elsevier B.V. All rights reserved.