The aim of this article is to discuss the theoretical issues behind reading processes, the relationbetween this skill and dyslexia, and to present some results from a pseudowords reading test with Portuguesechildren. Developmental dyslexia is a specific learning disability characterized by difficulty inlearning to read, and there is strong evidence that dyslexia is related to underlying deficiencies in phonologicalskills. Phonological deficits establish robust differences between dyslexic and normal readers and,according to the theoretical background, phonological awareness can be assessed with pseudowords tests.In this study, we applied the Pseudo words Reading Test, one of twenty tests of the Battery of Tests toAssess Developmental Dyslexia (BADD) constructed to assess dyslexia in Portuguese children between 7and 12 years old. We gave the Pseudo words Reading Test to 555 Portuguese children, aged 8 to 12.Fifty-seven of these children had been previously assessed by other professionals as dyslexics. We triedto verify how factors like age, gender and learning disabilities influence the acuity in pseudo words readingand if this test can be used to assist in an early diagnosis of developmental dyslexia. The results provethat there are significant differences between dyslexic children and normal readers in reading pseudowords in Portuguese language.