Background: Apart from a pervasive eating disorder, the Prader-Willi (PWS) syndrome is characterized by a distinct behavioural profile comprising maladaptive behaviours, obsessive-compulsive traits and skin picking, all included in the PWS behavioural phenotype. In this study, we present a further delineation of this characteristic behavioural profile by screening for indices of executive dysfunctions related to attention-deficit hyperactivity disorder (ADHD), immature compulsive-like adherence to sameness and skin picking, and how these features aggregate into symptom constellations in children and adolescents with PWS. Method: Parents of 58 individuals with PWS (aged 5-18 years) participated by completing Childhood Routines Inventory (CRI) and Conners Parent Rating Scale (CPRS-48). Results: Results showed that indices of ADHD and excessive insistence on sameness were common, comorbid and of early onset. They were both associated with conduct problems. Skin picking, appearing as a single and comorbid symptom, was less associated with childlike compulsions and ADHD-related problems. Conclusions: Findings are discussed in terms of further research in executive dysfunctions in PWS.