The purpose of this study is to explore how internal marketing practices affect the commitment of organizations’ “green” intellectual capital. It examines the relationship between internal marketing practices and the commitment to its “green” intellectual capital’s components: human, relational, and structural. Moreover, it investigates to what extent internal marketing practices are applied to strategic, operational, and implementation levels, affecting “green” intellectual capital commitment. A 27-item questionnaire was used to collect quantitative data. Six hundred nine employees from large companies operating in various business sectors in Greece participated in a survey from July to November 2020. The findings documented a strong impact of internal marketing practices (90.5%) on the commitment to “green” intellectual capital. Internal marketing practices applied at operational levels have the most substantial effect on the commitment of “green” intellectual capital (t= 17.387), while practices at implementation levels are not significant (t= 3.668). The results also indicated that internal marketing practices applied at strategic levels significantly influence the commitment to “green” intellectual capital (t= 15.747). Finally, the study discusses the theoretical and managerial contributions.