Hierarchically porous hematite (Fe2O3) nanostructures composed of aligned nanorods with diameters of about 12 nm have been synthesized via a one step thermal decomposition method of the commercial FeC2O4·2H2O powders. The porous structures and sizes of Fe2O3 nanostructures can be controlled by adjusting the calcination temperatures. This method is facile, high-yield and cost-effective for the large-scale mass production. When evaluated for lithium storage capacity, the hierarchically porous Fe2O3 nanostructures obtained from the calcination temperature of 400 °C exhibits high reversible discharge capacity (901.3 mAh g−1 at the initial lower rate of 0.2 C), superior rate performance (221.3 mAh g−1 at 10 C) and excellent cycling stability (416.4 mAh g−1 after 1000 cycles at 5 C). The reasons are explored in terms of the reduced diameters of nanorods and the finely constructed porous structures, which facilitate the fast and effective transfer of Li+ ions, and accommodate the large volume expansion during the charge and discharge cyclings. The facile one-step thermal decomposition method can be expected to open up opportunities in designing high-performance electrode materials with hierarchically porous features for lithium ion batteries.