Electrospinning of fibers composed of poly(3-hexylthiophene) (P3HT), fullerene derivative, phenyl-C(61)-butyric acid methyl ester (PCBM), and single-walled carbon nanotubes (SWNT) is reported. While of great promise for photovoltaic applications, morphological control of functional structures is a great challenge for most processing methods. It is demonstrated that the use of a tailor-made block-Copolymer for dispersion of individual SWNT enables the preparation of stable dispersions of individual tubes that may be further cospun from chloroform solutions with PCBM and P3HT into submicron fibers. The block copolymer used to mediate the colloidal and interfacial interactions in the combined system enables the spinning of centimeters long and uniform fibers. Structural characterization indicates a high degree of ordering and alignment within the fibers and absorption and quenching of the photoluminescence indicate significant interactions among the components. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1263-1268, 2011