Children and adolescents (henceforth "children") with both attention-deficit/hyperactivity disorder (ADHD) and anxiety experience greater difficulties than children with either alone, though qualitative methodologies are yet to be used to understand the challenges this population experiences. We aimed to explore parent-reported daily impacts of co-occurring anxiety in children with ADHD (ages 8-13 years). Participants were enrolled in an Australian trial evaluating an adapted anxiety intervention and were eligible if their child met diagnostic criteria for ADHD plus separation, social, and/or generalized anxiety disorder. A baseline measure of life impacts associated with child anxiety captured situations parents reported were difficult, due to their child's anxiety. Reflexive thematic analysis of free-text responses (N = 203) facilitated new insights via inductively generating key themes. Three overarching themes highlighted (1) child difficulties with everyday situations and processes due to their anxiety; (2) the nature of the child's anxiety being pervasive and unrelenting; and (3) the strain placed on the child's family system. This study enhances understanding of daily impacts associated with co-occurring anxiety and ADHD and may contribute to an improved understanding of support needs. Results reiterate the need to identify co-occurring difficulties in children with ADHD and support both children and their families.