This study examined the longitudinal relationship between early handwriting skills and the growth of spelling and reading skills in a large sample (N = 569) of 5- to 6-year-old children unselected for ability. The quality of children's handwriting was assessed using five indicators (letter form, slant, rhythm, ability, general appearance). Children also completed a wide range of tasks measuring reading, spelling and literacy-related skills (letter-sound knowledge, phoneme awareness, rapid automatized naming). A latent variable path model showed that variations in handwriting skills, but not generic fine motor skills, accounted for unique variance in the growth of spelling, but not reading. Theoretically, these findings suggest that writing words may lead to the creation of motoric representations of spelling patterns that support the development of children's orthographic knowledge. From an applied perspective, our findings suggest that practice writing words may help children to learn to spell them.