Electronic disorder in conducting polymers represents a fundamental limit for developing high performance polymer-based transistors (TFTs). Nanoscaled manipulation of polymer morphology with electrically inert nanostructures is an interesting and flexible strategy to enhance ordering in polymer films. We show that blending poly[2-methoxy,5-(3′,7′-dimethyloctyloxy)]-1,4-phenylene vinylene (MDMO-PPV) with silica nanoparticles leads to an increase in TFT performance, including an increase in hole mobility by over 10 times. By means of Raman spectroscopy we correlate variations in polymer structure induced by the silica to improvements in the electrical properties. We compare these results to MDMO-PPV blended with the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Although PCBM leads to similar results in longer channel TFTs, no improvement in short channel behavior is observed. These results demonstrate a simple way to realize short channel polymer TFTs with enhanced performance.