Dyslexia is a primary development disorder characterized by reading and writing disability. Although frequent, it remains underdetected at school and badly known by practitioners. As a consequence, many children remain severely handicapped in their school life, and later on in their adult social life, although being fairly intelligent. Pediatricians must be involved in its early detection and management. ERTL4 test is a useful test of detection to be applied in 5-7-year-old children.