Clinical practice guidelines summarise the existing evidence on specific health conditions and aim to optimise quality of care by providing evidence-based recommendations. Studies have reported a gap between research findings and clinical practice in physiotherapy. Guideline adherence is often used as a measure of agreement between therapeutic care and guideline recommendations. However, there is currently no standardised methodological approach for measuring guideline adherence. The objective of this scoping review was to summarise the methods and results of studies that assessed guideline adherence in physiotherapy. MEDLINE, EMBASE, PEDro and CENTRAL databases were searched for relevant literature up to December 2022. Published reports of observational studies and controlled clinical trials that provided information on the assessment of guideline adherence in physiotherapists were included. The selection process was performed independently by two reviewers. The methodological quality of the identified reports was not assessed. Results were summarised narratively. From a total of 2560 potentially relevant records, 53 reports were included in the analysis. Physiotherapists' adherence to guidelines was primarily assessed in the context of musculoskeletal conditions, such as low back pain (n = 25, 47.2%) and osteoarthritis (n = 8, 15.1%). A wide range of measurement approaches were used with the majority of reports using web-based surveys (n = 21, 39.6%), followed by chart reviews (n = 17, 32.1%). Most reports (n = 21, 39.6%) provided information on the level of adherence in terms of frequency dichotomising (self-reported) clinical practice as adherent or non-adherent. Adherence rates varied widely between included reports. Although the large number of included reports indicates a high level of interest in the topic of guideline adherence, there is considerable heterogeneity between studies regarding the methodological approaches used to assess guideline adherence in physiotherapists. This reduces the comparability of the study results. INPLASY (registration no. 202250081). Registered on 12th May 2022.