We report on the purification, crystal growth, and infrared (IR) spectroscopic properties of Pr-doped KPb 2 Cl 5 for applications in mid-IR solid-state lasers. KPb 2 Cl 5 has a narrow phonon spectrum extending to only ∼200cm −1 , which leads to small non-radiative decay rates and long-wavelength IR emission from trivalent rare earth ions. The synthesis of Pr:KPb 2 Cl 5 was based on the purification of commercial starting materials through baking under a dynamic vacuum, directional solidification, and multi-pass translation in a zone-melting system. The growth of the purified Pr:KPb 2 Cl 5 material was then carried out through vertical Bridgman technique employing a two-zone furnace. Under 1540nm diode laser excitation, Pr:KPb 2 Cl 5 exhibited a broad mid-IR emission band centered at 4.6μm, which was assigned to the 3 H 5 → 3 H 4 transition. The emission lifetime was determined to be 2.7ms at room temperature. Based on Judd–Ofelt analysis, the radiative lifetime was calculated to be 26.9ms, which results in a mid-IR emission quantum efficiency of ∼10% and a peak emission cross-section of 4.9×10 −21 cm 2 .