With the objective to demonstrate the real hidden capacities of reading in students with difficulties of learning such as dyslexia with the use of videogames, we have carried out a study with grammar education students. In order to do this, we have revised some literature to present and justify the real case study of an 8-year-old child with reading difficulties. Videogames have been used to show how he has improved his learning. To do this, we have tested his capacities with a standarized reading test (DIP-le) and we have done a follow-up with a videogame called DytectiveU, which is supposed to overcome his dyslexia. We have verified, with he same test, that the more the child plays this game, the better reading capabilities and abilities he develops. Finally, we demonstrate and verify the benefits of using videogames in psycopedagogical diagnosis and psycopedagogical tracing. We expect to increase the use of videogames in psycopedagogical clinics due to their great benefits.