Developmental language disorder (DLD) is a disorder characterized by difficulty with talking and/or understanding language which affects children and persist into adulthood. Throughout history, the terminology has changed. Since 2016, the label developmental language disorder has been accepted as a diagnosis given to people with language difficulties that have no apparent cause. The disorder is described in two major classifications, DSM-5 and ICD-10 which give a good overview of the characteristics of the disorder. DLD is a relatively common disorder that occurs with a prevalence of about 7,5%. People with DLD have difficulties in phonology, morphosyntax, semantics, pragmatics and even socio-emotional and academic areas. The adolescent period is most marked by socio-emotional difficulties and poorer academic performance. DLD is a very heterogeneous disorder and some people with DLD have been shown to have reading difficulties. The relationship between DLD and dyslexia/reading disorder is explained by three models: the severity model, the additional deficit model and the comorbidity model. Most adolescents with DLD have reading difficulties which is not surprising as language impairment is one of the main risk factors for reading difficulties. Difficulties in both aspects of reading, decoding and reading comprehension, are associated with poor phonological skills and difficulties in morphosyntax and semantics. Reading difficulties in adolescents with DLD affect educational achievement and that is why an early and proper intervention is of great importance (speech and language therapists, teachers...). Interventions in adolescents with DLD with reading difficulties are more successful when language and reading are addressed simultaneously in therapy.