In this report, Er3+/Ho3+/Pr3+ tri-doped fluoride glass was prepared. The enhancement of 2.7 and 2.9 mu m emissions from Er3+/Ho3+ doped system were achieved successfully after the addition of Pr3+. The combination of low OH- concentration, low maximum phonon energy and high mid-infrared transmittance is beneficial to the realization of mid-infrared emissions. The energy transfer mechanism among Er3+, Ho3+ and Pr3+ was investigated. The decay profiles of several levels were measured to further examine the enhanced mid-infrared emissions. Moreover, high stimulated emission cross sections at 2.7- and 2.9 mu m (1.08 x 10(-20) cm(2) and 2.0 x 10(-20) cm(2), respectively) were determined. Er3+/Ho3+/Pr3+ tri-doped fluoride glass might provide a new choice for mid-infrared laser. (C) 2015 Elsevier Ltd. All rights reserved.