Parental writing support was examined over time and in relation to children's language and literacy skills. Seventy-seven parents and their preschoolers were videotaped writing an invitation together twice during one year. Parental writing support was coded at the level of the letter to document parents' graphophonemic support (letter-sound correspondence), print support (letter formation), and demand for precision (expectation for correcting writing errors). Parents primarily relied on only a couple print (i.e., parent writing the letter alone) and graphophonemic (i.e., saying the word as a whole, dictating letters as children write) strategies. Graphophonemic and print support in preschool predicted children's decoding skills, and graphophonemic support also predicted children's future phonological awareness. Neither type of support predicted children's vocabulary scores. Demand for precision occurred infrequently and was unrelated to children's outcomes. Findings demonstrate the importance of parental writing support for augmenting children's literacy skills.