Developmental dyslexia is a deficiency in reading despite normal intelligence and adequate educational opportunities. Dyslexia is also associated with poor performance in a range of perceptual tasks, and it was previously suggested that benefits from regularities of sounds are reduced in dyslexia (Ahissar, 2006). In this study we tested whether long-term regularities of native language, to which we are exposed for many hours every day, are also less beneficial to individuals with dyslexia (IDDs). We tested that by manipulating familiar word structure (Hebrew morphology). IDDs showed a reduced benefit from familiar structure as compared to controls when they had to remember and read new words. However, structure familiarity was beneficial for IDDs when they were asked to emphasize speed while they read, and when they had to recognize novel words. These results imply that utilization of accumulated regularities is less efficient in dyslexia, though in some tasks this knowledge is accessible and beneficial.