Purpose: This study quantifies how intellectual capital and its human, structural and relational components relate to firm internationalization and export performance and compares their relative contributions using meta-analysis. Design/methodology/approach: Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we conduct a meta-analysis of 32 studies from Web of Science and Scopus, with a combined sample of 59,206 observations. The correlations are transformed using Fisher's r to z and synthesized with random effects models in R (metafor). We evaluate the heterogeneity using Q, I2 and t2 and assess publication bias using Egger regression, Kendall rank correlation and Rosenthal fail-safe N. Subgroup analyses compare the effects of human capital, structural capital and relational capital on internationalization and export performance. Findings: Overall, intellectual capital is positively and significantly associated with firm internationalization, but its association with export performance is not significant. Human capital and relational capital show positive and significant relationships with both internationalization and export performance. Structural capital is positively related to internationalization, while its association with export performance is positive but not significant. Together, these results clarify that the capability to enter and operate in foreign markets is supported by intangible assets in general, whereas export gains depend more directly on people and relationship-based resources beyond structural routines. Originality/value: This study addresses a clear and consequential gap by delivering a quantitative synthesis, which separates the effects of human, structural and relational capital across internationalization and export performance. By providing comparative, decision-relevant estimates, the study advances theory on intangible resources in international business and offers practical guidance for where managers and policymakers should prioritize investment to support market entry and export outcomes.