Ultrafine fibers of poly(methyl methacrylate) (PMMA)/poly(vinylidene fluoride) (PVDF) with unique core-shell structure were fabricated via facile electrospinning method, and were adopted as waveguide materials. PMMA, into which CdSe/ZnS quantum dots (QDs) were incorporated for efficient mode excitation, was employed as the core material, and PVDF was used as the cladding material for PMMA. These core-shell structured PMMA(QDs)/PVDF ultrafine fibers were electrospun in a one-step process by using two concentric syringes. The morphology of the PMMA(QDs)/PVDF ultrafine fibers was examined by field emission-scanning electron microscopy and transmission electron microscopy. The fluorescence of QDs dispersed in the PMMA/PVDF ultrafine fibers was measured via confocal laser scanning microscopy. The characterization of the light propagation by NSOM indicated that the electrospun PMMA/PVDF fibers containing CdSe/ZnS QDs functioned as an effective optical waveguide.