Motor neuron disease (MND), also known as amyotrophic lateral sclerosis, is a progressive, neurodegenerative condition which may cause dysphagia, as well as limb weakness, dysarthria, emotional lability and respiratory failure. Since normal salivary production is 0.5 to 1.5 litres daily, loss of salivary clearance due to dysphagia leads to salivary pooling and sialorrhea, often resulting in distress and inconvenience to patients. To systematically review evidence on treatment of sialorrhea in MND, including medications, radiotherapy and surgery. We searched the Cochrane Neuromuscular Disease Group Specialized Register (1 October 2010), the Cochrane Central Register of Controlled Trials )(CENTRAL) (The Cochrane Library issue 3, 2010), MEDLINE (January 1966 to September 2010), EMBASE (January 1980 to September 2010), AMED (1985 to September 2010) and CINAHL Plus (January 1937 September 2010). All bibliographies of the identified randomized trials were reviewed and authors contacted as needed. Known experts in the field were contacted to identify further published and unpublished papers. We included randomized and quasi-randomised controlled studies on any intervention for sialorrhea and related symptoms, in people with MND. Review authors summarised data independently in a customised data collection form and confirmed data presented in Cochrane Review Manager software. Only one randomized controlled trial was identified. This was a well designed study of botulinum toxin B injected into parotid and submandibular glands of 20 patients, which showed positive results for four weeks (Jackson 2009). There was low risk of bias in the study and no significant adverse events reported. There is some evidence for use of botulinum toxin injections to salivary glands for the treatment of sialorrhea in MND. Further research is required on this important symptom. Data are needed on the problem of sialorrhea in MND and its measurement, both by patient self report measures and objective tests. These will allow the development of better randomized controlled trials.