Although software localization has gained enormous momentum in the software sector in the past decades, little attention in the research world so far has been placed on the managerial perspective. This study fills this gap by examining a variety of key variables in localization project management and developing an approach to identify the critical factors for successful software localization. A four-step iteration method is applied to build a complete list of factors affecting the success of software localization. Based on previous research and the best practices in the industry, four propositions are formed, which are tested by the data collected from a survey sent to professionals in the industry from 14 countries. Subsequent in-depth interviews were conducted to verify the findings and to build insights into the industry. The survey result identified the critical success factors for each of the four categories. The most significant factors are highlighted to provide managerial insights for the managers of software localization.