Ecological momentary assessment has been increasingly used in autism studies over the last decade to capture and understand autistic people’s behaviours, thoughts, feelings and daily experiences. This systematic review synthesised previous autism ecological momentary assessment studies to learn about the feasibility of ecological momentary assessment with autistic people and derive ideas to optimise the applicability of ecological momentary assessment in autism studies. Five databases (MEDLINE, PsycINFO, Web of Science, EMBASE and CINAHL) were searched, covering the time between January 1990 and October 2024, for studies using ecological momentary assessment with autistic participants. We identified 32 studies with 930 autistic participants. These studies supported the acceptability and feasibility of ecological momentary assessment with young and middle-aged autistic adults with average or above-average intelligence and language skills. Previous researchers and autistic participants in the reviewed literature suggested considering adaptations in the design of sampling schedules, ecological momentary assessment questionnaires and the implementation of incentive strategies, to improve the applicability of ecological momentary assessment with the autistic population. Future ecological momentary assessment studies could address the limitations in the extant literature, for example, lack of evidence from youth and older autistic people and a wider range of study topics. Lay abstract Ecological momentary assessments assess people’s in-the-moment thoughts and behaviours in their daily lives in natural environments. The number of ecological momentary assessment studies with autistic people has increased over the last decade. For the first time, this review (1) summarises how well ecological momentary assessment works for allowing autistic people to describe and express their thoughts, emotions and experiences, and (2) provides suggestions for the design of ecological momentary assessment to make this research method more accessible to future autistic participants. In total, we synthesised participation experiences from 930 autistic people. Overall, ecological momentary assessment is generally acceptable for autistic adults aged from 18 to 60 and with average or above-average intelligence and language. We also identified several issues in the ecological momentary assessment procedure and suggested researchers consider these when designing future ecological momentary assessment studies with autistic people. The findings of this review provide evidence that ecological momentary assessment can be used to investigate many different questions with autistic people and suggest a wider application of ecological momentary assessment in future studies with autistic people.