Describing neural connectivity between pre-frontal and parietal brain regions and anxiety in children and adolescents with Autism Spectrum Disorder (ASD) has the potential to inform diagnosis and treatment decisions. This study aimed to identify the neural connectivity patterns between the prefrontal cortex (PFC) and parietal regions in young autistic males, and to determine if Generalised Anxiety Disorder (GAD) was associated with these communication patterns. Forty-one males with ASD aged between 6 and 18 yr (M age = 10.76 yr, SD = 3.14 yr) and their mothers were recruited as volunteer participants from the Gold Coast region, Australia. After assessments, participants received 3 min of eyes-closed and 3 min of eyes-opened EEG data-collection under resting conditions. EEG data from the frontal and parietal regions were investigated for their connectivity via Granger Causality (GC). There were significant correlations between the PFC-to-parietal region GC connectivity indices and total GAD scores, and also for the core components of GAD, but these were restricted to the alpha-wave frequency with only minimal beta-wave significant results. No significant correlations between parietal-to-PFC regions and GAD were present. Communication from the decision-making region (PFC) to the spatial reasoning (parietal) regions appeared to be aimed at instigating increased motor activity associated with GAD.