The present research was designed to investigate how children's early-acquired knowledge of letter names affects their spelling. Specifically, we asked whether kindergartners and first graders sometimes spell a sequence of phonemes such as /bi/ (the name of the letter b) or /zi/ (the name of the letter z) with the corresponding consonant letter rather than spelling the sequence alphabetically, with a consonant letter followed by a vowel letter. Children made a number of letter-name spelling errors, especially when the consonant and vowel formed a complete syllable. These results show that children's knowledge of letter names can cause them to deviate from the alphabetic principle-the principle that each phoneme should be represented with a single grapheme. The findings further suggest that syllables play a special role in early writing.