The outcome of a training study attempting to increase German speaking poor readers' reading fluency is reported. The aim of the training was to help children establish orthographic representations for a limited set of training words as well as for high-frequency onset clusters. A sample of 20 dysfluent readers (8 to 11 years) received a computerized training of repeated reading of a limited set of 32 training words over a period of up to 25 days. Each day, training words were presented up to six times with a special emphasis on the onset segment. Post-tests were carried out one and five weeks after the last training day. A considerable decrease in reading times could be achieved for the trained words that remained stable for both post-tests. However, even for the limited set of training words, a remarkable amount of repetitions did not lead to age adequate word recognition speed. Generalization to untrained words starting with a trained onset cluster (transfer words) was statistically reliable but small.