Photovoltaic devices based on organic semiconductors require charge-separating networks (bulk heterojunctions) for optimal performance. Here we report on the fabrication of organic-inorganic photovoltaic devices with tailored (n-type) CdSe nanorod arrays aligned perpendicularly to the substrate. The nanorod lengths varied from 58 +/- 12 to 721 +/- 15 nm, while the diameters and inter-rod spacings were kept constant at 89.5 +/- 7.5 and 41.3 +/- 9.9 nm, respectively. Short-circuit densities improved linearly with nanorod length, resulting in power conversion efficiencies of up to 1.38% for cells with nanorods 612 +/- 46 nm long. Notably, the cell's efficiency was dominated by exciton generation in the CdSe nanorods.