Epistemic injustice has undergone a steady growth in the medical ethics literature throughout the last decade as many ethicists have found it to be a powerful tool for describing and assessing morally problematic situations in healthcare. However, surprisingly scarce attention has been devoted to how epistemic injustice relates to physicians’ professional duties on a conceptual level. I argue that epistemic injustice, specifically testimonial, collides with physicians’ duty of nonmaleficence and should thus be actively fought against in healthcare encounters on the (...) ground of professional conduct. I do so by fleshing out how Fricker’s conception of testimonial injustice conflicts with the duty of nonmaleficence as defined in Beauchamp and Childress on theoretical grounds. From there, I argue that testimonial injustice produces two distinct types of harm, epistemic and non-epistemic. Epistemic harms are harms inflicted by the physician to the patient qua knower, whereas non-epistemic harms are inflicted to the patient qua patient. This latter case holds serious clinical implications and represent a failure of the process of due care on the part of the physician. I illustrate this through examples taken from the literature on fibromyalgia syndrome and show how testimonial injustice causes wrongful harm to patients, making it maleficent practice. Finally, I conclude on why nonmaleficence as a principle will not be normatively enough to fully address the problem of epistemic injustice in healthcare but nevertheless may serve as a good starting point in attempting to do so. (shrink)