This intervention study investigated the growth of letter sound reading and growth of consonant-vowel-consonant (CVC) word decoding abilities for a representative sample of 41 US children in preschool settings. Specifically, the study evaluated the effectiveness of a 3-step letter-sound teaching intervention in teaching preschool children to decode, or read, single letters. The study compared a control group, which received the preschool's standard letter-sound instruction, to an intervention group which received a 3-step letter-sound instruction intervention. The children's growth in letter-sound reading and CVC word decoding abilities were assessed at baseline and 2, 4, 6 and 8 weeks. When compared to the control group, the growth of letter-sound reading ability was slightly higher for the intervention group. The rate of increase in letter-sound reading was significantly faster for the intervention group. In both groups, too few children learned to decode any CVC words to allow for analysis. Results of this study support the use of the intervention strategy in preschools for teaching children print-to-sound processing.