Remediation studies of developmental dyslexia are extremely rare. We present a single case study of an 8-year-old German developmental dyslexic boy K.H. who is hypothesized to suffer from a severe memory problem, impeding the development of normal reading functions. The memory problem especially affects the storage and access to letter-sound associations. As a consequence, the boy was initially unable to accurately and quickly name most of the 26 letters of the alphabet. A multiple-baseline across-material design with a high-frequency errorless learning procedure was set up to improve letter-name associations. The intervention improved K.H.'s letter reading and even his word reading. We discuss the role of memory deficits in reading acquisition in the context of three different theoretical models. We show how such theoretical considerations can successfully guide remediation programmes.