The International Classification of Functioning, Disability and Health (ICF) Rehabilitation Set is proposed as a tool to measure functioning among a clinical population in Chinese rehabilitation services. It needs to be applied in a transparent and reliable way and considered from a measurement perspective. The aim of this study was to develop items operationalizing the ICF Rehabilitation Set to enhance the standardized and unified assessment in varied clinical settings. A list of proposed operational items was generated by (i) linking the items of four standard assessment instruments; (ii) literature review; and (iii) self-development. The candidate operational items were then evaluated by Chinese experts in rehabilitation medicine. One hundred and sixty-six operational items were generated using the three approaches and 54 were evaluated in the formal expert survey. Finally, 30 experts validated nine items from the assessment instruments, two found in the literature and 19 self-developed items for operationalizing the ICF Rehabilitation Set. The 30 operational items validated could potentially facilitate the implementation of the ICF Rehabilitation Set in clinical settings and provide a reference point for future research.