The literature has shown a strong relationship between executive dysfunction and Autism Spectrum Disorder (ASD), although there is no consensus on which subprocesses of executive functioning are impaired and/or preserved in this condition. This study aimed to investigate executive function and working memory in children and adolescents with ASD (n = 11) compared to children and adolescents with typical development (n = 19) matched by age, formal education, and nonverbal IQ. The tests used were: Raven’s Colored Progressive Matrices, Stroop Test, Trail Making Test, Rey’s Complex Figure Test, Digit span, Pseudowords span, Working memory, Verbal fluency (orthographic and semantic) and Go/no go. The results demonstrate impairment of executive function in the clinical group, especially in planning, flexibility, inhibition, and also visuospatial working memory.