Our objective is to determine the notable characteristics of phonological developmental dyslexia. We present the case of a normally intelligent 11-year-old child with an estimated reading acquisition age of 9 years. We used error analysis and testing methods (reading speed test, word identification test, reading comprehension test, verbal working memory test, morphological analysis test, phonological awareness test) as tools. The results show that child “Y” meets the criteria for phonological developmental dyslexia. The difficulty lies primarily in reading irregular words or pseudowords, reflecting an inability to use lettersound correspondences