Specific working memory deficits have been documented for different learning disorders (dyslexia, dyscalculia). Also children with attention deficit disorders (ADHD) have working memory problems especially with regard to executive functioning. There is a high rate of comorbidity of learning and attention disorders and yet, it is an open question, how this comorbidity might affect working memory functioning.We tested six groups of children with dyslexia (N=31), dyscalculia (N=18), ADHD (N=34), with dyslexia and ADHD (N=37), with dyscalculia and ADHD (N=21) and typically achieving control children (N=31). Working memory was assessed by a battery of 16 phonological, visual-spatial and central executive tasks, according to the model of Baddeley (1986).Results reveal distinct patterns of working memory deficits: dyslexia corresponds with deficits in phonological loop and dyscalculia with deficits in visual-spatial sketchpad. ADHD corresponds with deficits in central executive. No interaction effect could be detected. Thus, it should be concluded that the comorbidity leads to additive working memory deficits, i.e. children with both disorders must cope with broader deficits.