Purpose: Clinical supervision is widely accepted as an important element of practice for allied health professionals to ensure a high quality of patient care. However, it is unknown whether effective clinical supervision of allied health professionals improves patients' outcomes. This study investigated whether effective clinical supervision of allied health professionals is associated with improved patient functional independence. Methods: A prospective longitudinal study design and multi-level regression analysis were used to explore the association between effective clinical supervision and patient functional independence. The effectiveness of clinical supervision was assessed using the Manchester Clinical Supervision Scale. Functional improvement in patients treated by allied health professionals was measured utilising the mobility and self-care subscales of the functional independence measure.Results: Physiotherapists (n = 27) and occupational therapists (n = 26) in inpatient rehabilitation were recruited and the medical records of their patients (n = 1846) audited. The effectiveness of clinical supervision of physiotherapists was positively associated with improvement in personal care. Therapist variables accounted for less than 2.5% of the variation in patient improvement in functional independence.Conclusions: Effectiveness of a reflective model of clinical supervision of physiotherapists and occupational therapists was not associated with an improvement in their patients' mobility or personal care, respectively.Implications for rehabilitationEffective clinical supervision of physiotherapists and occupational therapists using a reflective model of practice is a poor predictor of improved functional independence in rehabilitation inpatients.Patient variables, such as the intensity of therapy, were more important predictors of patient functional improvement than effective clinical supervision.Initiatives aimed at increasing intensity of therapy will likely have a greater effect on improving patient functional independence compared with initiatives aimed at improving the effectiveness of clinical supervision using a reflective model of practice.Initiatives to improve the effectiveness of clinical supervision in improving quality of care could explore the use of a direct model of practice where supervisors directly observe and support supervisees during patient treatment sessions.