Uniform hvdroxvyatite nanorods with controllable sizes, aspect ratios (from 8-10 to above 100:1), and surface properties (hydrophobic or hydrophilic) have been successfully prepared by systematically tuning the interfaces between surfactants and the central atoms of hydroxyapatite using liquid-solid-solution synthesis. Hydroxyapatite nanorods like those shown in the figure may be useful in the development of organic-inorganic artificial bone.