ABSTRACT What mechanisms assure not just the presence of ethnic minority representatives but also the representation of their interests on political agendas? Research on this question has been limited. While some argue that a representative's ethnic identity is what is crucial, others point to the role of parties in substantive representation. Little research has empirically examined the role of ethnic parties specifically. Focusing on Ecuador, the first Latin American country to develop a successful Indigenous party, this research compares the impact of a strong Indigenous party, and Indigenous members of parliament on the substantive representation of Indigenous peoples. Quantitative analysis of the key factors behind the presentation of Indigenous interest bills over 20 years demonstrates that ethnic parties are key to advancing Indigenous interests.