Despite its public visibility and impact on policy, the activity of expert communication rarely receives more than a passing mention in codes of scientific integrity. This paper makes the case for an ethics of expert communication, introducing a framework where expert communication is represented as an intrinsically ethical activity of a deliberative agent. Ethical expert communication cannot be ensured by complying with various requirements, such as restricting communications to one's area of expertise or disclosing conflicts of interest. Expert communication involves morally laden trade-offs that must be weighed by a deliberative agent. A basic normative framework is introduced, and concrete provisions are proposed for codes of scientific integrity.