An increasingly blurred understanding of the conditions under which clinicians may withhold HIV seropositive status from partners of patients who are sexually active and who do not intend to disclose suggests a critical need to revisit the relationship between the principle of confidentiality, the moral and legal duties to warn at-risk third parties, and the organisational ethics surrounding licit cooperation with wrongdoing in the effort to uphold professional moral responsibility. This essay grounds its argument in two, straightforward premises: (i) the ethical principle of cooperation is an indispensable measure of the moral licitness of instances of complicity with wrongdoing; (ii) some instances of material organisational complicity vis-à-vis confidential withholdings of HIV seropositive status from partners of sexually active patients both meet and successfully employ the standards of the ethical principle of cooperation. Drawing from this syllogism, the essay argues that, in Type II cases, healthcare organisations may (initially and on certain conditions) materially cooperate in withholding the HIV seropositive status of patients from partners with whom patients are sexually active, and to whom patients do not intend to disclose HIV seropositive status, in the effort to honour professional obligations of privacy, confidentiality, and fidelity in a manner that is both legally licit and morally justifiable.