This study empirically investigates the impact of investment property holdings on tax avoidance and firm value among publicly listed companies in Korea. First, the analysis reveals that a higher proportion of investment properties is associated with reduced levels of tax avoidance. This finding suggests that such assets tend to increase the aggregate tax burden rather than serve as conduits for tax sheltering. Second, the results indicate that holding investment properties generally exerts a negative influence on firm value, manifesting in a valuation discount. However, this negative effect is significantly mitigated in firms with higher cash effective tax rates. This moderation suggests that a higher tax burden can suppress managerial agency problems and reduce political costs, thereby alleviating the adverse impact of investment property holdings on firm value. By synthesizing agency theory and the political cost hypothesis, this research provides new insights into the complex interplay between asset composition, tax strategies, and corporate valuation.