The Cellfield reading intervention is based on the multi-deficit theory of reading difficulties and addresses several foundation skills of reading simultaneously. Existing research has confirmed that the Cellfield intervention leads to improvement in reading skill directly following the intervention, but little data exist to determine the long-term efficacy of Cellfield. The present study investigated the long-term efficacy of the Cellfield intervention in a group of South African children. Fifty-two struggling readers were assessed via two standardised tests (Woodcock Reading Mastery Tests and Gray Oral Reading Test). Of the 52 readers, 41 underwent the Cellfield intervention, while 11 did not. Children were assessed on six reading variables before the intervention and directly following the intervention (treatment group). Both groups were re-assessed on the same variables at least a year after the intervention ended. Statistical analyses showed that advances in the treatment group directly after the intervention were maintained in the long term.