The aim of the study was to evaluate the effects of an intensive rehabilitation programme on thyroid metabolism, the relationship between disability and thyroid hormone level, and the occurrence of nonthyroidal illness syndrome (NTIS) before and after rehabilitation.This was a clinical prospective study. Orthopaedic surgery patients (n = 82) were classified into two groups: patients in whom early active mobilization and walking were possible (walking group, WG, n = 45), and patients in whom these were not recommended (nonwalking group, NWG, n = 37). Levels of free T3 (fT3), fT4, TSH and rT3 were measured before and after surgery, and then at 1, 3, 7, 14 and 30 days from the beginning of rehabilitation. Personal, nutritional and clinical data were acquired for all patients. The Barthel Index (BI) was used to assess disability before and after rehabilitation.