Although psychotherapy is generally efficacious, a substantial number of patients fail to improve meaningfully, whereas still others deteriorate. Moreover, psychotherapists have difficulty forecasting which patients are at risk for nonresponse or deterioration, especially when relying predominantly on their judgment. These limitations have implications for the ethical practice of psychotherapy, and they call for remediation strategies. One such strategy involves the use of routine outcomes monitoring (ROM), or the regular collection of core patient progress information that can be fed back to the clinician and patient in real time. ROM-informed analytics outperform clinical judgment in predicting patients who are on or off track for treatment success, which can help psychotherapists plan and responsively adjust their interventions. Additionally, research demonstrates that ROM-generated feedback improves treatment outcomes for the average case who receives versus does not receive it. ROM data can also uncover between-therapist differences in general efficacy, as well as scientifically highlight clinicians' own relative strengths and weaknesses in treating different mental health problems. In light of such evidence, we submit that the research on ROM has matured to the point that it should occupy a central role in discussions of, and guidelines about, the ethical practice of psychotherapy. In this vein, we discuss ROM at patient, psychotherapist, and mental health care systems levels; namely, for each of these stakeholders, we review the extant empirical support before turning to possible ethical implications. Finally, we offer concluding thoughts on the expanding relevance of ROM for helping psychologists fulfill their ethical practice obligations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).