Background Compulsory treatments represent a legal means of imposing treatment on an individual, usually with a mental illness, who refuses therapeutic intervention and poses a risk of self-harm or harm to others. Compulsory outpatient treatment in psychiatry, also known as community treatment order, is a modality of involuntary treatment that broadens the therapeutic imposition beyond hospitalization and into the community. Despite its existence in over 75 jurisdictions worldwide, COT is currently one of the most controversial topics in psychiatry, and it (...) presents significant ethical challenges. Nonetheless, the ethical debate regarding compulsory treatment almost always stops at a preclinical level, with the different ethical positions arguing for or against its use, and there is little guidance to support for the individual clinicians to act ethically when making the decision to implement COT. Main body The current body of evidence is not clear about the efficacy of COT. Therefore, despite its application in several countries, evidence favouring the use of COT is controversial and mixed at best. In these unclear circumstances, ethical guidance becomes paramount. This paper provides an ethical analysis of use of COT, considering the principlist framework established by Ross Upshur in 2002 to justify public health interventions during the 2002–2004 severe acute respiratory syndrome outbreak. This paper thoroughly examines the pertinence of using the principles of harm, proportionality, reciprocity, and transparency when considering the initiation of COT. Conclusion Ross Upshur’s principlist model provides a useful reflection tool for justifying the application of COT. This framework may help to inform sounder ethical decisions in clinical psychiatric practice. (shrink)