This article describes a systematic review and critical evaluation of the international literature on the effects of physical therapy, speech pathology, and occupational therapy for people with motor neuron disease (PwMND). The results were interpreted using the framework of the International Classification of Functioning, Disability and Health. This enabled us to summarize therapy outcomes at the level of body structure and function, activity limitations, participation restrictions, and quality of life. Databases searched included MEDLINE, PUBMED, CINAHL, PSYCInfo, Data base of Abstracts of Reviews of Effectiveness (DARE), The Physiotherapy Evidence data base (PEDro), Evidence Based Medicine Reviews (EMBASE), the Cochrane database of systematic reviews, and the Cochrane Controlled Trials Register. Evidence was graded according to the Harbour and Miller classification. Most of the evidence was found to be at the level of "clinical opinion" rather than of controlled clinical trials. Several nonrandomized small group and "observational studies" provided low-level evidence to support physical therapy for improving muscle strength and pulmonary function. There was also some evidence to support the effectiveness of speech pathology interventions for dysarthria. The search identified a small number of studies on occupational therapy for PwMND, which were small, noncontrolled pre-post-designs or clinical reports.