The book-gifting programme, the Letterbox Club, was developed as a response to the increased interest in ways of improving the educational outcomes of children in out-of-home care. By reporting quantitative and qualitative findings from a Swedish trial, and compiling findings from previous British evaluations, the purpose of this paper is to further our understanding of the programme's potential impact. Pre/post measurements of the reading age of 72 foster children showed an average improvement of 2.5 months in comparison to the national average. With some exceptions, interviews with children and carers showed that the programme was well received and indicated that it could increase reading engagement and carer involvement. The current empirical base knowledge suggests that the Letterbox Club has a small impact on foster children's literacy. The results do not allow for causal interpretations. Long-term outcomes are unknown. The programme lacks a theoretical foundation, and the implementation is dependent on individual and contextual factors. However, the programme is simple to administer, low-cost, and can reach a large number of children. The article therefore suggests that the Letterbox Club could be seen as a general supportive measure, and promotion of carer involvement is proposed as a way of improving its potential impact.