While numerous studies have suggested that the New Engineering Contract (NEC) can improve cost control and reduce disputes through enhanced collaboration, its practical implementation presents both opportunities and challenges. To further advocate for NEC and standardize practices, the Development Bureau has developed the NEC Hong Kong Edition specifically and mandated its use for all public works projects there; however, execution barriers still remain. This research examines the strengths and weaknesses of implementing NEC to manage construction project costs in Hong Kong. Adopting a mixed-methods strategy, this study administered 102 questionnaires and conducted three in-depth semi-structured interviews to explore construction professionals’ open views. Surprisingly, the findings indicate that respondents' perceptions of NEC’s benefits are only moderate, with most below 3.5, except for the top benefit, which is NEC streamlining cost monitoring processes in projects. Barriers were generally rated 3.5 to 4.0, with the top two being “complicated compensation event procedures” and “limited awareness of the cost benefits from using NEC”, implying a knowledge gap among the Hong Kong construction professionals. Furthermore, the Kruskal-Wallis test indicated that respondents across various professional positions have significantly different perceptions of the limited awareness that hinders NEC adoption. These results suggest that despite government mandates, NEC has not been effectively promoted or integrated into practice. The study recommends further training and collaboration within the industry to enhance understanding of the NEC system to facilitate a successful transition to its use for cost management in Hong Kong.