The good electrical and morphological characteristics of TiO2 nanofibers and the high extinction coefficient of CH3NH3PbI3 perovskite are combined to obtain a solar cell with a power conversion efficiency of 9.8%. The increase of the film thickness dramatically diminishes the performance due to the reduction in porosity of the TiO2 nanofiber framework. The optimum device (similar to 413 nm film thickness) is compared to a planar device, where the latter produces higher V-oc but lower J(sc), and consequently lower efficiency at all measured light intensities.