This review is concerned with structural and morphological properties of inorganic / organic nanocomposites synthesized by the homogeneous precipitation method, along with their mesostructured derivatives. The nanocomposites presented are layered or hexagonal mesostructured aluminum and rare earth oxides templated by alkyl sulfate assemblies and calcium phosphates templated or complexed with alkyl- α -amino acids. The hexagonal mesostructured rare earth (Y, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) oxides serve useful as a precursor to form mesoporous materials with specific surface areas of as large as 545 m²g^-1 (Y system) and about 300 m²g^-1 (Eu-Gd systems) by anion exchange with acetate ion, although the alumina-based analogues collapse on the removal of surfactant. The as-grown and acetate-treated hexagonal mesostructured materials also show versatile and biomimetic morphologies such as tubular, multi-ringed, worm-like, disk-like and dish-like shapes. The surface patterns of the layered mesostructured materials also resemble those of coral or radiolarian. In the animo acid added calcium phosphate systems, furthermore, neutral but polar or basic group bearing amino acids yield hydroxyapatite predominantly, whereas n-alkyl amino acids produce octacalcium phosphate with an accompanying increase in crystallinity, expansion in cell volume depending on their alkyl chain length and enantiomerism. Aspartic acids form an amino acid complexed octacalcium phosphate. The nanocomposites or their derivatives presented here are promising as absorbing, separating, optoelectronic, filler, biofunctional or other functional materials.