The productivity of machine tools is significantly improved by using microcomputer based CAD/CAM systems for NC program generation. Currently, many commercial CAD/CAM packages that provide automatic NC programming have been developed and applied to various cutting processes. One of the cutting processes machined by CNC machine tools is hole-cutting operations (HCO). In this paper, we attempt to find an efficient solution approach to determine the best sequence of operations for a set of holes that located in asymmetrical locations and different levels. In order to find the HCO that achieves the shortest cutting tool travel path (CTTP), Genetic algorithm is introduced. After the CTTP is optimized, the G-codes that use to code the part of program for this process is created. CTTP can be formulated as a special case of the traveling salesman problem (TSP). The incorporation of genetic algorithm and TSP can be included in the commercial CAD/CAM packages to optimize the CTTP during automatic generation of NC programs.