This study is a neuropsycholinguistic research of a rare genetic syndrome with microdeletion that co-occurs with intellectual disabilities and relatively good language abilities, the Smith-Magenis Syndrome (SMS). Nevertheless, there are no cognitive and psycholinguistic profile analyses performed with Spanish population. In this sense, we characterized the cognitive and psycholinguistic profile of a sample with 9 participants with SMS (7 to 11 years of age). The cognitive and psychological profile was assessed with diverse standardized tests: Wechsler Intelligence Scale for Children - IV version, Illinois Test of Psycholinguistic Abilities and Peabody Picture Vocabulary Test. Results suggest a specific cognitive and psychological profile characterized by a low IQ and relative good abilities in integrating information, whereas attention problems and hyperactive behaviors were displayed when interacting with the child during the assessment. This work is the first evidence of the cognitive and psycholinguistic profile characterization in patients with SMS in Spain, and will help to guide a more accurate diagnosis and differential intervention in rare genetic diseases with similar cognitive and psycholinguistic profiles.