Is conscientious objection (CO) necessarily incompatible with the role and duties of a healthcare professional? An influential minority of writers on the subject think that it is and make various types of claim about the source of the incompatibility. In this paper, we begin by outlining the positive case for accommodating CO, before addressing one particular type of incompatibility claim, namely that CO is fundamentally incompatible with proper healthcare professionalism. The attitude of the conscientious objector, it is claimed, exists in opposition to the sort of disposition (attitudes and underlying character) that we are entitled to expect from a 'good' healthcare professional. We begin here by asking whether this claim is true in principle: what is the disposition of a 'good' healthcare professional, and how does CO align with or contradict it? Having concluded that, at least in principle, CO need not contradict or undermine good professionalism, we move on to consider practical compatibility, acknowledging that this will involve the identification of appropriate limits on the exercise of CO and considering briefly what those limits might be. Ultimately, we reject the suggestion that CO is fundamentally incompatible-either in principle or in practice-with good healthcare professionalism.