In this study, luminescence electrospun (ES) nanofibers based on ternary blends of poly(9,9-dioctylfluoreny-2,7-diyl) (PFO)/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)/poly(methyl methacrylate) (PMMA) were prepared from chloroform solutions using a single capillary spinneret. Effects of PFO/MEH-PPV ratio on the morphology and photophysical properties were studied while the PMMA weight percentage was fixed at 90 wt%. The morphologies of the prepared ES fibers were characterized by FE-SEM and fluorescence microscopy. The obtained fibers had diameters around a few hundred nm and pore sizes in the range of 3035 nm. The emission colors of the PFO/MEH-PPV/PMMA blend ES fibers changed from blue, white, yellowish-green, greenish-yellow, orange, to yellow, as the MEH-PPV composition increased. In contrast, the emission colors of the corresponding spin-coated films were blue, orange, pink-red, red, and deep-red. Based on the values of solubility parameters, the PFO and MEH-PPV are miscible to each other and trapped in the PMMA matrix. Hence, energy transfer between these two polymers is possible. The smaller aggregated domains in the ES fiber compared to those of spin-coated films possibly reduce the efficiency of energy transfer, leading to different emission colors. Also, the prepared ES fibers had higher photoluminescence efficiencies than those of the spin-coated films. Pure white light-emitting fibers prepared from the PFO/MEH-PPV/PMMA blend ratio of 9.5/0.5/90 had the Commission Internationale de L'Eclairage (CIE) coordinate of (0.33, 0.31). Our results showed that different color light-emitting ES fibers were produced through optimizing the composition of semiconducting polymer in the transparent polymer matrix. This type of ES fibers could have potential applications as new light sources or sensory materials for smart textiles. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 463-470, 2009