Measurement-based care is an approach to clinical care that involves systematically evaluating patient-reported outcomes to guide clinical decision making with a strong evidence base in the general population; however, its use in autism is limited. As autistic people are more likely to be diagnosed with psychiatric disorders (e.g. depression, anxiety) and to use psychiatric services (e.g. psychotherapy) than the general population, efforts to enhance clinical care for this population are critical. The current proof-of-concept study presents the development and pilot administration of an autism-adapted measurement-based care (MBC-AUT) system for psychotherapy designed for and with autistic people, as well as preliminary data on the feasibility, acceptability, benefits, and barriers to the adoption of the system for clients and clinicians. Findings from the first 18 youth and adult clients to use the system suggest that the MBC-AUT system is feasible and acceptable. Important benefits of the MBC-AUT system for clients and clinicians were identified through semi-structured interviews, and some barriers to the use of the MBC-AUT system were raised. Potential solutions are presented to address these barriers and to reduce the client and clinician burden. As autistic clients continue to seek psychological services, efforts to enhance the delivery and quality of psychotherapy for this population are essential. Lay abstract Autistic youth and adults are more likely to experience psychiatric symptoms (e.g. depression, anxiety) and to use psychiatric services than non-autistic people, yet research on evidence-based approaches to enhance psychiatric care for autistic people is limited. Measurement-based care is an evidence-based approach to psychotherapy that improves outcomes for clients, clinicians, and organizations by routinely administering and evaluating measures to clients. Despite this, research on measurement-based care systems for autistic clients is sparse. To address this gap, we developed an autism-adapted measurement-based care (MBC-AUT) system for and with autistic people and pilot tested the system in an outpatient psychiatry clinic to investigate the preliminary feasibility, acceptability, benefits, and barriers to this system for clients and clinicians. Findings suggested that the MBC-AUT system was a feasible and acceptable system for the first 18 autistic youth, their caregivers, and autistic adults to use the system. In semi-structured interviews, clients and clinicians discussed the benefits of the MBC-AUT system to various therapeutic processes, as well as several important barriers to the use of the system. We offer potential solutions to address these barriers and to reduce client and clinician burden, and propose future directions for this line of research to increase access to more autistic people. As autistic clients continue to seek psychological services amid social landscapes of increasing complexity (e.g. COVID-19 pandemic), efforts to enhance the delivery of psychotherapy for this population are critical.