This paper considers evidence from an intervention designed to raise standards in spelling and independent writing. "The Complete Spelling Programme" (McMurray and Fleming, 1998) is designed to ensure that all processes involved in learning to spell are activated and that the interaction between them is facilitated. In addition, a number of innovative features within the programme's design allow sources of spelling knowledge to be presented in a developmental sequence, allowing all children to learn together, regardless of their ability. The programme provides day-to-day spellings and an extensive range of follow-up activities, clearly differentiated, linking spelling to wider literacy teaching, e.g. grammar, language understanding, punctuation. The impact of the programme on progress, not only in spelling tests but also in spelling accuracy and quality in independent writing, was assessed by means of a longitudinal study with a 2x2 quasi-experimental design. The two independent variables were (i) experimental school (intervention) or control school (no intervention) and (ii) high or low social disadvantage. A sample of 81 children aged 5-6 years across the four schools was followed for three years from Year 2 to Year 4 (Northern Ireland). A range of quantitative measures was used for baseline assessment and to establish the quantifiable outcomes for children in both the experimental (N=43) and the control schools (N=38). Qualitative measures were used to illuminate the processes involved in the programme in the experimental schools (McMurray, 2004). At the end of the study pupils who had been taught using the programme had made significant improvement in spelling and independent writing. On the basis of the findings it is argued that spelling needs to be seen as an integral tool in raising standards in literacy and that it should not be taught in isolation from other literacy skills.