Purpose. The goal of the current study is to gain an understanding of how various informal institutional elements such as trust and corruption control affect the relationship between entrepreneurial ventures’ social capital and their ability to reach the worldwide market. Design/Methodology/Approach. The paper draws on internationalization and social capital data from the Global Entrepreneurship Monitor (GEM), which includes 482,257 observations from 44 countries between 2003-2013, with a focus on early-stage entrepreneurs (as defined by the TEA index) who are involved in significant international entrepreneurial entry. A multi-level modelling strategy is employed for analyzing the various hypotheses by using STATA. Findings. Possessing a high level of social capital makes it easier to start a business at the international stage. And further, informal institutional variables, i.e., trust and control of corruption, positively moderate the association between social capital and international entrepreneurial entry; thus, societies where honesty prevails and corruption is controlled facilitate better international entrepreneurial entry. Limitations/Implications. The study is based on informal institutions, i.e., the variable trust taken from the World Value Survey (WVS) and the variable control of corruption by using a large sample size and multi-level modelling from World Governance Indicators, which demonstrates the importance of institutions as systems of shared meanings and noncodified standards. However, there are a number of other informal institutional indicators to examine that could have an impact on the relationship at the individual level. Implications from a theoretical perspective explain advancement of the institutional perspective as a conceptual framework for explaining international entrepreneurial activity and, further, the study empirically validates the significance of informal institutional environmental factors in the context of international entrepreneurship. Originality/Value. With the increasing interest of scholars in using the institutional approach and the availability of limited empirical studies in light of informal institutions, using a multi-level approach the current study empirically investigates the role of trust and control of corruption in the context of social capital and international entrepreneurship. Keywords: social capital, internationalization, international entrepreneurship, informal institutions