The International Classification of Functioning, Disability and Health (ICF), designed by the WHO, attempts to provide a holistic model of functioning and disability by integrating a medical model with a social one. The aim of this article is to analyze the ICF’s claim to holism. The following components of the ICF’s complexity are analyzed: (1) health condition, (2) body functions and structures, (3) activity, (4) participation, (5) environmental factors, (6) personal factors, and (7) health. Although the ICF claims to be (...) holistic, it presupposes a monistic materialistic ontology. We indicate some limitations of this ontology, proposing instead: (a) a pluralistic–holistic ontology (PHO) and (b) a multidimensional view of the human being, with individual and environmental aspects, in relation to three levels of reality implied by the PHO. For the ICF to attain its holistic claim, the interactions between its components should be based on (a) and (b). (shrink)