Knowledge of letter-sound correspondences underpins successful reading acquisition, and yet little is known about how young children acquire this knowledge and what prior information they bring to the learning process. In this study, we used an experimental training design to examine whether either prior letter awareness or prior phonemic awareness directly assists preliterate children in subsequently learning letter-sound correspondences. Here 76 preschoolers received 6 weeks of training in either letter awareness, phonemic awareness, or control tasks and then received a further 6 weeks of training in either letter-sound correspondences or control tasks. There was limited evidence that prior training in either phoneme or letter awareness directly assisted learning of letter-sound correspondences, although phonemically trained children appeared to show some advantage on recognition tasks. Overall, the data suggest that there is little value in training preschoolers in either letter forms or sounds in isolation in advance of providing instruction on the links between the two.