alpha-FeOOH nanorods with diameters of 15-25 nm and lengths up to 170-300 nm were synthesized in high yield via a facile and template-free hydrothermal method at low temperature. After calcining the as-synthesized alpha-FeOOH at 250 degrees C for 2 h, we could obtain alpha-Fe2O3 nanorods. Interestingly, the as-obtained alpha-Fe2O3 nanorods exhibited weakly ferromagnetic characteristics at low temperature and superparamagnetic property at room temperature, which is different from the behavior of the corresponding bulk material.