<p>The present study aims to examine whether the amount and type of writing instruction (basic skills and composing process) and children’s writing practice (copying and generative writing) predict children’s writing achievement. Additionally, it investigates whether the relationship between writing instruction and practice and writing achievement depends on children’s entering skills in writing. The study included 78 kindergarten teachers and 449 kindergarten children from three states in the United States. Teachers were videotaped three times during the academic year (fall, winter, and spring). Assessments of children’s letter writing, spelling, and composition were conducted in the fall and again in the spring. Multilevel models showed that composing process instruction significantly predicted children’s spring letter writing when controlling for their fall skills. Similarly, copying practice significantly predicted children’s spring letter writing skills after accounting for their fall scores. However, the impact of the amount and type of writing instruction and practice did not depend on children’s initial writing skills. These findings highlight the importance of composing process instruction and copying practice in enhancing children’s letter writing skills.</p>