Propagation effects in liquid crystal-core optical fiber waveguides have been investigated. In theory, propagation properties of the TE01and TM01modes in the waveguide composed of a low-birefringence nematic liquid crystal acting as an optical-fiber core have been analyzed. For smaller diameters of the liquid crystal-core, the TE01mode is guided and TM01is the leaky mode, but for larger diameters differences between both modes decrease. The paper presents initial experimental transmission characteristics of the liquid crystal fiber subjected to the influence of selected external perturbations. The experimental results have been compared with the theory in view of some typical optical fiber parameters suggesting a great potential of the liquid crystal-core fibers for environmental sensing.