Monodispersed aluminum-substituted hematite particles were synthesized from concentrated mixed solutions of FeCl3 and AlCl3 using the gel-sol process. With increasing aluminum content (Ay(Fe + Al)) in the starting solutions, hematite particles became more and more elongated. The product particles exhibited ellipsoidal, rod- and peanut-like shapes, depending on Al concentration. Higher Al content (> 20 mol%) in the system greatly suppressed the formation of hematite, Atomic emission spectrometry analysis and lattice parameter measurement confirmed the substitution of Al in hematite particles,