Dystonia is a hyperkinetic movement disorder involving repetitive or sustained muscle contractions, resulting in abnormal postures. Proposed underlying pathophysiological mechanisms include neuronal network dysfunction, disruption to inhibitory processes and impaired synaptic plasticity. Here, we perform a systematic literature review of diffusion MRI brain studies of genetic and idiopathic forms of dystonia, aiming to identify brain regions and pathways consistently implicated in dystonia. Embase and PubMed databases were searched (to October 2021) for terms relating to diffusion MRI and idiopathic and inherited forms of dystonia. Of 40 identified studies, 10 assessed inherited, 24 idiopathic and 6 mixed types dystonia. The imaging methodology employed was variable, with key limitations including data acquisi- tion and processing steps. Study cohorts were also often small, particularly for Mendelian inherited forms. The most consistent abnormalities identified were lower FA (fractional anisotropy) and reduced number of tractography streamlines in white matter connecting the brainstem, cerebellum, basal ganglia and sensorimotor cortex. Findings were consistent across genetic and idiopathic forms of dystonia, although greater variability was seen in findings from idiopathic cohorts. Overall, microstructural white matter dif- ferences between dystonia cohorts and controls are evident, however the imaging measures used are often non-specific, with broad potential to its underlying biological meaning.