While developmental dyslexia has been extensively studied in children, research on adults is still rather limited. This paper aims to bridge the gap in existing research by presenting the findings of a study that examined the reading and spelling skills of adults with dyslexia and assessed the effectiveness of a linguistic intervention designed to improve their literacy abilities. To address this issue, we first compared the profiles of 44 adults with dyslexia (age range: 16-30 y.o.) and 44 age-matched typical readers across tasks assessing reading, spelling, phonological awareness, morphological awareness and lexical access in Italian. The findings underscored pervasive impairments in dyslexia across all measured dimensions, reaffirming the persistent nature of language and literacy challenges into adulthood. In pursuit of the second objective, the study explored the potential for literacy skill improvement in adults with dyslexia through the implementation of a specialized intervention proposed to 24 dyslexic adults and delivered via a web application. The intervention program yielded positive outcomes in the experimental group, demonstrating significant improvements in word and text reading, spelling, and speed of phonological elaboration. This study, hence, contributes not only to our understanding of developmental dyslexia in adulthood but also emphasizes the tangible benefits of targeted linguistic interventions, thereby offering practical implications for the amelioration of literacy skills in this population.