Dyslexia is a specific learning disability which result in people having difficulties with phonological processing. Persons with dyslexia have poor phonological decoding abilities and deficit in development of phoneme-grapheme connections. Dyslexia is mostly diagnosed after development of automatic reading at the age of 9. Children in this research are 9 or 10 years old. Dyslexia is not due to either lack of intelligence or poor teaching. It has negative effect on acquiring school knowledge, but difficulties may be reduced with early treatment and individual approach. The aim of this study is to examine the influence of phonotactic probability on lexical processing in children with dyslexia. The study included 27 children with specific language impairment and 20 children with typical language development. Childre were supposed to read words and pseudowords on lexical decision task. Some of the words and pseudowords had sequences of low phonotactic probability and some had sequences of high phonotactic probability. The task measured the time of reaction and the accuracy of the answers. The data was analized considering the effects of lexicality and phonotactic probability between the two groups. It was found that there is statistically significant effect of phonotatic probability on the accuracy of the answers and there is statistically significant effect between groups on the time of reaction and on the accuracy of the answers.