WHAT IS KNOWN ON THE SUBJECT?: The use of chemical restraint in emergency situations is to control aggression or violence to protect consumers and staff and is to be used as a last resort when all other behavioural control alternatives have been exhausted. Chemical restraint involves the use of medication. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: This is the first paper to systematically review the prevalence of the use of chemical restraint. The use of chemical restraint is common across emergency departments and acute psychiatric inpatient units worldwide. Consumers who are restrained are also likely to receive chemical restraint. The studies reviewed demonstrate that there is a need for more standardized data collection so that clearer comparisons can be made between healthcare settings and countries. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Implications of practice include the need to report adverse events post-chemical restraint as these can deleteriously affect a person's physical health. Identification of and staff education about first-line management techniques before chemical restraint is administered are significant to reduce its use. ABSTRACT: Introduction Chemical restraint is used to manage uncontrolled aggression, agitation or violent behaviours of consumers with mental health disorders admitted to acute psychiatric or emergency settings. Aim This systematic review aimed to synthesize the international prevalence of chemical restraint for non-consenting adults. Method PsycINFO, CINAHL, MEDLINE/PubMed and Google Scholar databases were searched for peer-reviewed literature published between January 1996 and July 2018. This paper reports on data extracted from retrospective audits of chemical restraint practice. Results Forty-eight papers were included. The median prevalence of use of any restraint was 21.2% (25th% 8.0 to 75th% 36.3). Median prevalence of people who were chemically restrained, of all people restrained in any manner, was 43.1% (25th% 22.9% to 75th% 70.7%). Of all people admitted to facility(ies), the median prevalence of chemical restraint was 7.4% (25th% 2.7 to 75th% 17.6). There was no statistically significant difference in any prevalence measure considering healthcare setting or country. There was a significant decrease over the review period in the use of any restraint, including chemical restraint. Discussion and implications for practice This is the first known comprehensive meta-view of chemical restraint use worldwide, highlighting the need for standardized data collection to enable comparisons between healthcare settings and countries. Relevance statement There is an international imperative to reduce or eliminate the use of coercive practices, such as physical and chemical restraint, in mental health care. This study provides important information for mental health nursing by synthesizing the international prevalence of chemical restraint for non-consenting adults. This meta-view of the worldwide use of chemical restraint can inform ongoing efforts to reduce its use.