An infrared photonic crystal fiber has been made by multiple extrusions of silver halide (AgClxBr1−x) crystalline materials. The core of the fiber consisted of pure AgBr, and the cladding area included fiberoptic elements made of AgCl (with lower refractive index). Fibers of outer diameter 1 mm and length of the order of 1 m were flexible and transparent in the spectral range 3–20 μm. Measurements of the power distribution and the transmission losses in the fibers indicated that they behave like core-clad structures, with an effective core diameter 200 μm. These fibers will be extremely useful for many applications in the middle- and far-infrared.