<p>The role of national intellectual capital in fostering and sustaining economic growth has gained increasing recognition, particularly within the framework of the knowledge economy. Furthermore, the long-term prosperity of citizens is closely tied to the effectiveness of a nation institutions. Despite this understanding, the interplay between institutional quality and the relationship between national intellectual capital and citizen prosperity has not been thoroughly investigated. We examine the impact of national intellectual capital on citizen prosperity and the moderating effect of institutional quality on this relationship. Utilizing the autoregressive distributed lag (ARDL) model, we analyze data from the ASEAN-5 countries covering the period from 2000 to 2022. Our findings indicate a significant positive correlation between national intellectual capital and citizen prosperity across these nations. However, this beneficial effect is tempered by improvements in institutional quality, particularly observed in Cambodia and Malaysia over both the short and long term, as well as in Vietnam in the short term. These insights suggest that effective policy strategies aimed at enhancing citizen prosperity should prioritize strengthening institutional quality. The results of this research provide valuable implications for policymakers seeking to leverage national intellectual capital for sustainable economic development.</p>