This final report describes the motivations, activities and results of the hydrogen storage independent project 'High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides' performed by the United Technologies Research Center under the Department of Energy Hydrogen Program, contract No. DE-FC36-02AL67610. The objectives of the project were to identify and address the key systems technologies associated with applying complex hydride materials, particularly ones which differ from those for conventional metal hydride based storage. This involved the design, fabrication and testing of two prototype systems based on the hydrogen storage material NaAlH4. Safety testing, catalysis studies, heat exchanger optimization, reaction kinetics modeling, thermochemical finite element analysis, powder densification development and material neutralization were elements included in the effort.