Many children with Autism Spectrum Disorder (ASD) have diverse cultural and linguistic backgrounds. Research shows that bilingualism does not lead to language delays in children with ASD; however, no research evaluated the optimal procedures to teach two languages. Our first aim is to compare the acquisition of a small vocabulary when (a) teaching two languages simultaneously, (b) teaching two languages sequentially, and (c) teaching one language only (control). We hypothesize that children with ASD will learn two languages simultaneously better than sequentially. Our second aim is to identify the effects of the aforementioned teaching conditions on the maintenance of a small vocabulary in two languages. We hypothesize that the longer the duration of the training, the better the maintenance. We also hypothesize that participants will demonstrate better maintenance when learning two languages simultaneously. Our third aim is to evaluate the effects of the aforementioned conditions on the translation of a small vocabulary in the two languages. We hypothesize that children will demonstrate better translations when learning two languages simultaneously. These findings will have direct implications for clinical practice. Besides, our long-term goal is to develop larger-scale projects aimed to establish optimal procedures for teaching two languages to children with ASD. Identifying the optimal order of teaching these languages represents an important first step towards this goal.