OBJECTIVE: To conduct a systematic review of the clinical research evidence on homeopathy in the treatment of anxiety and anxiety disorders. METHODS: A comprehensive search of major biomedical databases: MEDLINE, EMBASE, ClNAHL, PsycINFO, Cochrane Library; and of specialist complementary and alternative medicine (CAM) databases: AMED, CISCOM and Hom-Inform was conducted. Efforts were made to identify unpublished and ongoing research using relevant sources and experts in the field. Relevant research was categorised by study type and appraised according to study design. Clinical commentaries were obtained for studies reporting clinical outcomes. RESULTS: Eight randomised controlled studies were identified. The types of anxiety and anxiety disorders studied were test anxiety, generalised anxiety disorder and anxiety related to medical or physical conditions such as cancer or surgical procedures. Single case reports/studies were the most frequently encountered study type but other study types including uncontrolled trials/case series and surveys were also found. No relevant qualitative research was identified. CONCLUSIONS: A comprehensive search demonstrates that the evidence on the benefit of homeopathy in anxiety and anxiety disorders is limited. A number of studies of homeopathy in such conditions were located but the randomised controlled trials report contradictory results, are underpowered or provide insufficient details of methodology. Several uncontrolled and observational studies reported positive results including high levels of patient satisfaction but because of the lack of a control group, it is difficult to assess the extent to which any response is due to homeopathy. Adverse effects reported appear limited to 'remedy reactions' and included temporary worsening of symptoms and reappearance of old symptoms. On the basis of this review it is not possible to draw firm conclusions on the efficacy or effectiveness of homeopathy for anxiety. However, surveys suggest that homeopathy is quite frequently used by people suffering from anxiety. If shown to be effective, it is possible that homeopathy may have benefits in terms of adverse effects and acceptability to patients. Consequently, further investigation is indicated. Future research should be of pragmatic design and include qualitative studies.