<p>This study investigates the complex relationship between front-end technical fuzziness, knowledge sharing, leadership capability, and project performance in high-tech new product development environments. Front-end technical fuzziness (FTF), often arising during the early stages of new product development, introduces significant uncertainty that can negatively impact project outcomes. Previous research has shown conflicting findings regarding how knowledge sharing and leadership capability influence the impact of front-end technical fuzziness on project performance. To address this, the study explores how these factors moderate the relationship between front-end technical fuzziness and project performance, focusing on both individual and project-level dynamics. Using hierarchical linear modeling, data was collected from 941 project members across 196 teams in a science and technology research institute in Taiwan. The results indicate that front-end technical fuzziness negatively impacts project performance, but knowledge sharing and leadership capability serve as significant positive moderators, reducing the detrimental effects of front-end technical fuzziness. Both knowledge-sharing and leadership capability also have direct positive effects on project performance. This research contributes a novel multi-level framework, integrating individual-level front-end technical fuzziness with project-level moderators, offering a more comprehensive understanding of how these dynamics interact. The study underscores the importance of fostering a knowledge-sharing culture and developing leadership capabilities to improve new product development outcomes in high-tech industries. Practical implications include the need for strong leadership and an environment that encourages open communication to mitigate technical uncertainties in new product development projects.</p>