Background Joint hypermobility syndrome (JHS) is a heritable connective tissue disorder characterised by excessive range of movement at multiple joints accompanied by pain. Exercise is often the mainstay of management yet research evidence for its effectiveness is unclear. Objectives This systematic review aimed to determine the effectiveness of therapeutic exercise for JHS. Methods Data sources included nine online databases (AMED, BNI, CINAHL, Cochrane Library, Embase, HMIC, Medline, PEDro and SPORTDiscus), hand search and snowballing. Search terms reflected concepts of 'joint hypermobility syndrome' and 'therapeutic exercise'. Study eligibility criteria were: people diagnosed with JHS (rather than asymptomatic generalised joint laxity); therapeutic exercise (of any type) used as an intervention; primary data reported; English language; published research. Due to the small number of studies identified in initial scoping work, specific types of exercise or clinical outcomes were not prescribed. All study designs were included. The methodological quality of included articles was appraised individually by each reviewer using Critical Appraisal Skills Programme checklists. They were then discussed collectively and disagreements resolved through debate. Results 2,001 titles were identified. Four articles met the inclusion criteria and were included in the final review, comprising one randomised controlled trial, one randomised comparative trial and two cohort studies (see references). One study was conducted in a paediatric population and three in adults. Two investigations studied the knee joint whilst the others incorporated generalised exercise. Total sample sizes ranged from n=20-57 (with n=15-30 in the exercise arms). Standardised effect sizes for pain ranged from 0.75-1.72. The evidence suggests improvement over time in a range of patient (and parent) reported outcomes (including pain, global assessment of the impact of hypermobility, maximum distance walked and quality of life) and objective outcomes (including proprioception, balance, strength and range of movement). Importantly, however, there was no convincing evidence that improvements were any better than comparator groups. The only randomised controlled trial failed to report between-group statistical analyses. The randomised comparative trial found no difference between generalised exercise and joint-specific exercise. No adverse effects of exercise were reported. Conclusions There is some evidence that people with JHS improve over time with exercise but there is no convincing evidence that one form of exercise is better than another or that exercise is better than doing nothing. The methodological quality of the included studies was generally lacking, particularly with regards statistical power and adequate control conditions. Further robust studies are required to determine the effectiveness of therapeutic exercise for the management of JHS.