An experimental study has been conducted to measure the size of aluminium agglomerates during the combustion of nano-/micro-aluminized composite solid propellants. The combustion products of the propellant are quenched at a short distance from the burning surface and collected using a quench collection set-up. Nano-aluminium exhibits significant agglomeration, but only a small fraction of the agglomerates are in the 1-3 μm range. When large-sized coarse and fine AP particles are used in the formulation, the agglomerate size is greater, but does not exceed ∼5 μm. Copyright © 2010 by the American Institute of Aeronautics and Astronautics, Inc.