Thoracic outlet syndrome (TOS) is a debated topic. While there are many clinical studies concerning the efficacy of surgical treatment, there are few regarding conservative treatment. It has not yet been established whether or not conservative treatment is effective and what the best treatment is. The aims of this study were to evaluate the efficacy of conservative treatment in TOS with particular reference to physiotherapy, orthotics, and taping and to make general recommendations for conservative treatment. The literature was reviewed. Medical databases consulted: Medline, Embase, CINAHL, Current Awareness, Pedro, Cochrane Library, Medscape. We used the following key words: thoracic outlet syndrome, double crush syndrome, entrapment, conservative, treatment, rehabilitation, and management. Languages of the articles reviewed: English, French, German, Spanish, Italian, and Portuguese. This analysis focussed on 10 studies of conservative treatment and 3 studies comparing the outcomes of conservative and surgical treatment, published from 1983 to 2001. This review found no randomised controlled trials, systematic reviews, or meta-analyses. Conservative treatment seems to be effective at reducing symptoms, improving function, and facilitating return to work, also when compared to surgery. We could not establish whether or not conservative treatment was better than no treatment or placebo, or what type of conservative treatment was the best.