The present day composite propellants use micron sized aluminium powders, as fuel, to effect improvement in flame temperature and density. Micron sized aluminium particles agglomerate at the burning surface and make large particles which burn in the gas phase causing two-phase flow loss and poor combustion efficiency. Replacement of micron sized aluminium powder with nano sized powder could result in improvement of propellant burn rates, combustion efficiency as well as reduction in the two phase flow loss. Hence improvement in specific impulse (Isp.) could be expected. However, introduction of nano-aluminium also causes retardation to propellant curing reactions leading to poor mechanical properties. The viscosity of nano aluminized propellant slurries are extremely high and propellant casting becomes very difficult. These factors prevent the industrial level production of nano-aluminized propellants. The motivation of this work was to mitigate these limitations. The objectives were three-fold. The first objective was to develop a nano-aluminium based solid rocket propellant meeting the current specifications of physico-mechanical properties. In this regard, a HTPB based nano-aluminized propellant with 86% solid loading and 18% nano-aluminium content was successfully developed. The problem of poor mechanical properties could be overcome by suitably tailoring the HTPB microstructure and other network linkages of the binder system. A GAP based nano-aluminized propellant is also being developed. The selected formulation has higher theoretical energetics than the 18% aluminized HTPB propellant. Development and characterization of this propellant system is being carried out. As a part of the second objective of this R&D, the problem of high viscosities during casting was overcome by upgrading the casting technology from vacuum casting to pressure casting. A novel pressure casting apparatus has been developed. The casting apparatus was qualified through live propellant castings of high viscosity micro-aluminized propellants. The third objective of this work is to test the developed propellants by Ballistic Evaluation Motors having 3kg propellant mass. To this effect, a BEM has been designed and developed. A total of 06 firings of micro-aluminized propellants were carried out. It is proposed to undertake nano-aluminized BEM firings in future.