The mobility enhancement of organic thin-film transistors based on poly(3-hexylthiophene) (P3HT) by incorporating gold nanorods (Au NRs) is reported. Through varying the doping concentration and surface modifier of the Au NRs in P3HT matrix, the P3HT/Au composite with 0.5 mg mL(-1) pyridine-capped Au NRs exhibits a hole mobility of 0.059 cm(2) V-1 s(-1), this value is seven times higher than that of pristine P3HT. This remarkable improvement of mobility originates from the enhanced crystallinity and optimized orientation of P3HT after doping with Au NRs. In addition, the appropriate surface modification can produce more-efficient hole conduction of Au NRs.