BackgroundArt therapy is a form of complementary therapy to treat a wide variety of health problems. Existing studies examining the effects of art therapy differ substantially regarding content and setting of the intervention, as well as their included populations, outcomes, and methodology. The aim of this review is to evaluate the overall effectiveness of active visual art therapy, used across different treatment indications and settings, on various patient outcomes.MethodsWe will include randomised controlled studies with an active art therapy intervention, defined as any form of creative expression involving a medium (such as paint etc.) to be actively applied or shaped by the patient in an artistic or expressive form, compared to any type of control. Any treatment indication and patient group will be included. A systematic literature search of the Cochrane Library, EMBASE (via Ovid), MEDLINE (via Ovid), CINAHL, ERIC, APA PsycArticles, APA PsycInfo, and PSYNDEX (all via EBSCOHost), ClinicalTrials.gov and the WHO’s International Clinical Trials Registry Platform (ICTRP) will be conducted. Psychological, cognitive, somatic and economic outcomes will be used. Based on the number, quality and outcome heterogeneity of the selected studies, a meta-analysis might be conducted, or the data synthesis will be performed narratively only. Heterogeneity will be assessed by calculating the p-value for the chi2 test and the I2 statistic. Subgroup analyses and meta-regressions are planned.DiscussionThis systematic review will provide a concise overview of current knowledge of the effectiveness of art therapy. Results have the potential to (1) inform existing treatment guidelines and clinical practice decisions, (2) provide insights to the therapy’s mechanism of change, and (3) generate hypothesis that can serve as a starting point for future randomised controlled studies.Systematic review registrationPROSPERO ID CRD42021233272