Spanish is one of the most widely spoken languages in the world. Quechua is the largest indigenous language family to constitute the first language (L1) of second language (L2) Spanish speakers. Despite sheer number of speakers and typologically interesting contrasts, Quechua-Spanish second language acquisition is a nearly untapped research area, due to the marginalization of Quechua-speaking people. This review considers contributions to the field of second language acquisition gleaned from studying the grammars of Quechua speakers who learn Spanish as well as monolingual Quechua and Spanish speakers in the contact area. Contribution to the documentation and revitalization of the Quechua languages is discussed as an ethical and scientific imperative. (Contains 3 tables and 9 notes.)