Visible solid-state lasers based on upconversion glass fiber waveguides are attractive because upconversion, the resonant conversion of near-infrared (NIR) to visible light, permits high laser power in narrow bands and the fiber geometry guarantees a high exciting NIR radiation density along the entire absorption medium. The synthesis of the first upconversion fibers based on a heavier halide (ZnBr2) is reported. A modified fiber preparation process that decreases the risk of attack by moisture is described and the losses along the fiber investigated.