Dye-doped submicron poly(N-vinylcarbazole) fibers having mean diameters of 290-430 nm were fabricated via electrospinning and their waveguiding properties were investigated. The middle of each fiber's length was excited with UV light and guided photoluminescence (PL) was measured at the end of each of the fibers for different propagation lengths. The spectral shapes of the guided PL differed depending on the fiber diameter because of leakage of light into the substrate. We propose a model that reproduces the PL attenuation with increasing propagation lengths and includes the temporal PL decay due to photobleaching and the size of the excitation area. The calculated propagation loss coefficient in the fibers was 6.3 x 10(-3)-1.4 x 10(-1) mu m(-1) with lambda=430-500 nm. The propagation loss was inherent in the fiber itself because the reabsorption loss coefficient of the doped dye was <1.3% of the propagation loss coefficient. (C) 2016 Wiley Periodicals, Inc.