Children diagnosed with autism spectrum disorder (ASD) commonly experience significant deficits in social communication, besides restricted and repetitive activities and patterns of behaviors. This neurodevelopmental disorder often has a negative impact on their family members, particularly their mothers. The likelihood of developing symptoms of Generalized Anxiety Disorder (GAD) among mothers of children with ASD is elevated due to the daily challenges they encounter in caregiving. The present study aims to evaluate the prevalence of generalized anxiety disorder among mothers of children with autism spectrum disorder. Using a case study approach, this comparative study included 45 mothers of children with ASD, including 15 mothers of children with mild ASD, 15 with moderate ASD, and 15 mothers of children with severe ASD, to answer the question; is there a relationship between the severity of ASD in children and GAD among their mothers? The ages of participants ranged between 26 and 39 years. This study was conducted in several associations dedicated to supporting children with neurodevelopmental disorders in the Beni Mellal region, where their mothers attend these associations frequently. The prevalence of GAD in this sample was assessed using the Mini International Neuropsychiatric Interview (MINI), in its Moroccan Arabic version. This study’s outcomes confirmed the high prevalence of GAD among mothers of children with ASD, with a positive correlation between the severity of ASD among children and the probability of having generalized anxiety disorder in their mothers.