The purpose of this study was to develop a grounded theory about the joking behaviors of psychiatric unit staff. Fifty nine staff members (Male = 23, Female = 36), ages 28-62, who worked in an urban, public facility were observed in unit meetings over a two year period. Data were analyzed using the constant comparative method. Participants used aberrant humor to deal with the basic social process of facing a series of ultimately unresolvable problems. The factors involved included the organizational context of the working environment, contact with a stigmatized patient group, and stressful staff-patient interactions which led to the erosion of a sense of professional competence and the resulting demoralization, resentment, and vengeful counteraction. Two major categories of joking emerged: whimsical and sarcastic humor. Six subcategories of humor also emerged: incongruous, bravado, self-mocking, discounting, malicious and gallows humor. Staff engaged in more sarcastic than whimsical humor. Findings support the need for professionals to recognize the potentially detrimental effects of joking behaviors on their treatment effectiveness.