Although humor in health care can facilitate relationship building between patients and clinicians, callous humor used to deflect or dismiss distressing emotions undermines relationships, erodes trust, and expresses disregard for vulnerability. Because it affects collegiality, training, and patient care, callous humor should not be tolerated, especially when directed at patients. This article considers why it is important to respond to colleagues who make callous jokes and suggests how to do so. Functions of Humor in Health Care It's likely that humor is as old as healing. Hippocrates, for instance, advised his patients to "contemplate on comic things" to facilitate recovery. 1 Today, one would be hardpressed to find many physicians prescribing laughter and humor for patients, although clinicians frequently use humor. Indeed, humor in clinical settings can be welcomed by patients, and understandably so: humor and joking can put some patients at ease, level power imbalances, facilitate relationship building, and help patients articulate things they might otherwise be afraid to say. 2,3,4,5 Humor can also help clinicians relieve tension, make people on a health care team feel better, and even alleviate burnout. 6,7 Ultimately, humor can bring feelings of levity, pleasure, and connection as well as mutual understanding to situations that might otherwise feel bleak, tragic, or lonely. Humor also has drawbacks with which many clinicians are familiar. 8 Gallows humor or jokes that are callous, derogatory, or cynical are common, although usually shared out of earshot of patients and their loved ones. 9 While some see this kind of humor as useful in a work environment plagued with suffering and death, 9 others have argued that it dehumanizes patients, undermines trust in practitioners, erodes the character of health care as a sector, and fosters cynicism and detachment among trainees during crucial phases of their professional development. 10,11,12 Indeed, callousness, whether manifest in a joke specifically or in an insensitive demeanor more generally, might indicate that one has experienced moral damage or distress-and such distress can cause health care practitioners to become less responsive to the needs and concerns of others. 13 Moral distress-the deep anguish practitioners feel when they are aware of not acting as they are motivated to act-can result from persistent, systemic issues like productivity and efficiency pressures, feelings of powerlessness in the face of patients'