<p>The concept of epistemic injustice provides a theoretical framework for considering the ethical issues arising in interpersonal communication. This article proposes the concept of implicational injustice as a novel type of epistemic injustice. An implicature is a message that a speaker does not explicitly state, but that is implicitly communicated by an utterance. Since the speaker does not explicitly state the implicature, it may be overlooked by the hearer. This oversight of implicature is likely to occur when the hearer prematurely terminates the search for relevance or when there is informational inequality between speaker and hearer. If premature termination or information inequality is caused by the hearer’s prejudice against the speaker or by the undue ignorance of the speaker, the oversight of implicature is deemed an implicational injustice. This article offers several examples of the oversight of implicature and implicational injustice in doctor-patient communication in which patients’ attempts to convey psychosocial messages to their physicians are often overlooked. Implicational injustice can be considered as a novel subtype of epistemic injustice that differs from other subtypes, such as silencing, testimonial injustice, and interpretative injustice. Implicational injustice prevents the sufferer’s full participation in epistemic collaboration and can inflict secondary harm, such as negative effects on clinical decision making.</p>