Abstract This study focused on the precursors of spelling difficulties in first grade for children with specific language impairment (SLI). A sample of 58 second-year kindergartners in the Netherlands was followed until the end of first grade. Linguistic, phonological, orthographic, letter knowledge, memory, and nonverbal-reasoning skills were considered as precursors, as was spelling level at an earlier point in time. Spelling difficulties at the end of first grade were most accurately identified by letter knowledge at the beginning of first grade and word spelling at the middle of first grade. It is concluded that spelling development in children with SLI can be seen as an autocatalytic process in which, without intervention, poor spellers generally remain poor spellers, and good spellers remain good spellers. A focus on early spelling intervention is thus emphasized.