We have demonstrated, for the first time to our knowledge, lasing at 1.37 μm in a tellurite-based glass host doped with 0.5 mol.% neodymium: Nd3+:(0.8)TeO2–(0.2)WO3. The gain-switched laser could be operated with 59 μJ threshold pulse energy as well as 5.5% slope efficiency. As high as 6 μJ-pulses with a duration of 1.74 μs were obtained. The pulse repetition rate was 1 kHz. The emission cross section from the threshold analysis turned out to be 1.57×10−20 cm2 at 1370 nm by taking into account excited-state absorption from 4F3/2 to 4G7/2 energy level. Furthermore, the ratio of excited-state absorption to the emission cross section was found out to be 0.78 by using the slope efficiency value.