This study evaluates Reading Intervention--a 10-week supplementary reading programme emphasising the link between phonological awareness and reading--when delivered in a realistic educational setting. Twenty-nine 6-year-olds with reading difficulties participated in Reading Intervention and their progress and attainments were compared with those of a representative control group from the same classes, matched on age and gender. Language profiles were also explored. Children with reading difficulties showed weaknesses in phonological awareness and literacy as well as nonphonological oral language skills and nonverbal reasoning. During the intervention, the intervention group made significantly greater progress than the control group in early word reading, phoneme awareness and phonetic spelling. Over a 6-month follow-up period, the intervention group maintained its gains but during this time made significantly less progress on single word reading, phoneme awareness and phonetic spelling than the control group. These findings provide evidence that reading interventions can be delivered effectively in standard educational settings. We argue that a better understanding of how to manage withdrawal of intervention and how to address poor readers' additional oral language weaknesses is needed.