Anxiety and stress are everyday issues for many people with high-functioning autism, and while cognitive-behavioural therapy is the treatment of choice for the management of anxiety, there are challenges in using it with people with high-functioning autism. This study used modified experience sampling techniques to examine everyday anxiety and stress in adults with high-functioning autism and to explore the feasibility of delivering real-time stress management techniques using a mobile platform. High levels of anxiety were found to be characterised by worry, confusing thoughts and being alone but was not associated with internal focus, imagery or rumination. Participants reported improved mood and less worry and anxious thinking in the active phase of the study. These results support previous studies indicating that people with high-functioning autism differ in their experience of anxiety and provided preliminary data on the feasibility of real-time stress management. The limitations of this approach are discussed together with considerations for future work in the area of developing clinical interventions on mobile platforms.