The first main function of IOs is articulation and aggregation. This refers to the ability of IOs to bring together unions or organizations that focus on similar issues.

The second significant function of IOs is norm-setting. International organizations greatly contribute to the creation of new norms. They also encourage states to involve in norm-setting processes.

The third function of IOs is recruitment. This refers to their organizational capacity to allow new members to become a member of the international community with full rights.

The fourth main function of IOs is socialization. In general, socialization can be considered as a learning process of states about values. INGOs can enable people who share the same beliefs to get socialized at the international level. IOs including MNCs contribute to socialization via diffusing cultural and social values.

Other three significant functions of IOs are rule-making, rule application, and rule adjudication.