Discussions of conscientious objection (CO) in healthcare often concentrate on objections to interventions that relate to reproduction, such as termination of pregnancy or contraception. Nevertheless, questions of conscience can arise in other areas of medicine. For example, the intensive care unit is a locus of ethically complex and contested decisions. Ethical debate about CO usually concentrates on the issue of whether physicians should be permitted to object to particular courses of treatment; whether CO should be accommodated. In this article, I focus on the question of how clinicians ought to act: should they provide or support a course of action that is contrary to their deeply held moral beliefs? I discuss two secular examples of potential CO in intensive care, and propose that clinicians should adopt a norm of conscientious non-objection (CNO). In the face of divergent values and practice, physicians should set aside their personal moral beliefs and not object to treatment that is legally and professionally accepted and provided by their peers. Although there may be reason to permit conscientious objections in healthcare, conscientious non-objection should be encouraged, taught, and supported.