Aim: This descriptive article considers aspects of healthcare complexity and clinical education through the World Health Organisation's International Classification of Functioning, Disability and Health (ICF). The relevance of the ICF for informing healthcare for people with complex health needs is considered and implications for clinical education are suggested. Method: The 'core sets' of 22 complex health conditions were extracted from the official ICF internet research database. These core sets, which have been developed with almost 6000 patients and experts globally, define the key dimensions and implications of these complex health conditions using standardised descriptors. Relevant descriptors were summarised as tallies of all categories across the 22 core sets. Results: The categorised tallies indicated that across 22 complex conditions, the ICF domains of 'activities and participation', 'environment' and 'body function' were used more frequently in core set inventories documenting complex conditions than descriptors from the 'body structures' domain. That is, personal, social and environmental dimensions were highlighted more frequently than medical aspects of complex conditions. Conclusion: The ICF 'core sets' for complex health conditions provide a useful, research-based perspective on healthcare complexity. The current study suggests that clinical education for complexity should likewise be broad in scope and include the multiple personal, social and environmental dimensions of complexity.