Functional (i.e., logic) verification of the current generation of complex, super-scalar microprocessors such as the PowerPC 604™ microprocessor presents significant challenges to a project's verification participants. Simple architectural level tests are insufficient to gain confidence in the quality of the design. Detailed planning must be combined with a broad col- lection of methods and tools to ensure that design defects are detected as early as possible in a project's life-cycle. This paper discusses the methodology applied to the functional verification of the PowerPC 604 microprocessor.