This study used a multiple probe across participants' research design to evaluate the effects of instruction on the acquisition of letter-sound correspondences (LSCs) by three young children with autism spectrum disorder and limited speech. All three children (ages 3-5 years) reached criterion for identifying the LSCs targeted during instruction, and a Nonoverlap of All Pairs (NAP) analysis showed evidence of medium to strong treatment effects. All three children also provided evidence of maintenance and generalization of LSC skills to other tasks. Implications for instruction and future research directions are discussed.