The morphology and charge transport characteristics of electrospun aligned nanofibers based on the 2D conjugated polythiophene derivative P4TDPP are studied. The crystallinity, orientation, and molecular packing of P4TDPP nanofibers are significantly enhanced by a crystalline-induced technique. P4TDPP nanofiber transistors exhibit a high hole mobility of 0.305 cm(2) V(-1) s(-1) and on/off ratio of 1.30 x 10(5), which is significantly higher than that of the corresponding spin-coated film (2.10 x 10(-2) cm(2) V(-1) s(-1)). The experimental results suggest that high-performance FETs can be obtained from electrospun aligned nanofibers of crystalline conjugated polymers.