This longitudinal study examined the relationship between kindergarten word writing and grade 1 literacy in a large sample of Israeli children. In kindergarten, a majority of children produced writing which displayed most of the graphospatial characteristics of conventional word writing, although only one-third of the children demonstrated a working knowledge of the alphabetic principle. Kindergarten writing significantly predicted variance in all three measures of grade 1 literacy (decoding, spelling, and reading comprehension), even after controlling for general intelligence. We also investigated the role of alphabetic skills and socioliteracy variables in accounting for the predictive power of kindergarten writing. Kindergarten alphabetic skills (phonemic awareness and knowledge of letter names), but not socioliteracy factors (parental print exposure, parents' reading to child, and Clay's Concepts about Print), explained all the variance contributed by kindergarten writing to grade 1 decoding and spelling. In the case of reading comprehension, both alphabetic and socioliteracy variables were able to account for the predictive power of kindergarten writing. As a precursor of reading comprehension, kindergarten writing appears to reflect both domain-specific alphabetic skills and broader socioliteracy factors underlying the higher order cognitive competencies essential for comprehending text.