The purpose of this paper is to present a qualification methodology for software tools for nuclear safety I&C applications. When tools are used for development or verification & validation (V&V) of safety instrumentation & controls (I&C) software, their correctness has to be assured so that the tools can perform their intended function and would not mask any errors in software being developed or V&Ved. Therefore, it is important to thoroughly evaluate tools before they are used. The evaluation using proven methodologies shall result in confidence in using the tools because they are then qualified. IEEE Std 7-4.3.2-2003 provides guidance for qualifying software tools, which requires that software tools used to support software development processes and V&V processes shall be controlled under configuration management. One or both of the following methods shall be used to confirm the software tools are suitable for use: First (1), a test tool validation program shall be developed to provide confidence that the necessary features of the software tool function as required. And second (2), the software tool shall be used in a manner such that defects not detected by the software tool will be detected by V&V activities. Finally, tool operating experience may be used to provide additional confidence in the suitability of a tool, particularly when evaluating the potential for undetected defects.