IntroductionStandardised testing is crucial for autistic children to receive appropriate interventions, necessary services, and funding. Behaviours associated with autism can hinder children's test performance and participation. The 18‐item, two‐page Occupational Therapy Observation Tool–Adjustment Support Details (OTOT‐ASD) is used in conjunction with standardised assessments. The OTOT‐ASD enables the recording of autism‐related behaviours and the reasonable assessment accommodations made to support participation in testing. The current study aims to investigate the content validity and clinical utility of the OTOT‐ASD from occupational therapists' perspectives.MethodA specifically designed online questionnaire was distributed Victoria‐wide to occupational therapists with clinical experience with autistic children. The questionnaire was designed in line with the COnsensus‐based Standards for selection of health Measurement INstruments (COSMIN), including relevance, comprehensiveness, and comprehensibility of items evaluated for content validity. Applicability and clinical usefulness were also investigated. Quantitative data were analysed using descriptive statistics.ResultsSeventy‐one occupational therapists responded to the questionnaire and 46 provided a full dataset. Over 96% of the respondents considered documenting behaviours and testing accommodations as important, yet less than 45% reported having resources to record this information. Ninety‐five percent of the respondents perceived the OTOT‐ASD to be useful in clinical practice. Over 70% agreed that OTOT‐ASD items were significantly relevant to practice and comprehensive. To improve comprehensibility, identified items were altered following feedback.ConclusionThe findings suggest that the OTOT‐ASD is clinically useful and content validity is sound. Further research on other psychometric properties of the OTOT‐ASD and users' qualitative experiences in utilising the tool is recommended.