Holes in multiple circular patterns exist in several recent industrial parts such as antennas, heat exchanger support plates, condensers, boilerplates, trammel screens and separators. There is a lot of difficulty in preparing CNC programs using conventional programming or canned cycle programming. This study illustrates an effort to establish a practical common algorithm allowing the drilling of holes arranged in multiple circular patterns. The programmed algorithm can easily be adapted to any modern CNC unit to create a user cycle or subroutine. To test the capabilities of this algorithm, two case studies were developed. The first used the Numeripth800-B CNC unit equipped with a horizontal Orion-500 machining center, and the second case study was developed using the Sinumeric 840-D equipped with a vertical Emco machining center. A number of samples were produced successfully. The new algorithm shows high efficiency in the part program establishment and offers the advantage of decreasing the encoding errors.