We examined the longitudinal predictors of nonword decoding, reading fluency, and spelling in three languages that vary in orthographic depth: Finnish, Greek, and English. Eighty-two English-speaking, 70 Greek, and 88 Finnish children were followed from the age of 5.5 years old until Grade 2. Prior to any reading instruction, they were administered measures of phonological awareness, letter knowledge, and rapid naming speed. In Grade 2, they were administered measures of nonword decoding, text-reading fluency, and spelling. The results showed that the model for nonword decoding in Greek was similar to that of Finnish (both have consistent grapheme-to-phoneme mappings) while the model for spelling in Greek was similar to that of English (both have some inconsistent phoneme-to-grapheme mappings). In addition, the models for nonword decoding and spelling in Finnish were similar, because Finnish is consistent in both directions. Letter knowledge dominated the prediction in each language. The predictable role of orthographic consistency on literacy acquisition is discussed.