Many papers state the significant role of continuous improvement (CI) in achieving efficient and effective organization. Process performance can be enhanced with CI practice since it can create knowledge about the process and make process change happen. The emphasis of the research was placed on adopting continuous improvement system in organizations which then supports a positive effect on internal process performance. In this relation, management support was analysed as a moderator variable that can strengthen the relationship between continuous improvement system and internal process performance. In order to examine the set hypothesis, a research model was developed, and a survey was conducted on 113 Croatian companies that hold ISO 9001 certificate. To analyse this relation, regression analysis was performed. The results of the study showed that the link between continuous improvement system and internal processes performance is significant. Also, the results confirmed that management support strengthens the relationship between continuous improvement system and process performance.