This study examined a model of stress and cognitive appraisal as it applies to burnout in hospital social workers providing services to AIDS patients. The research was done in response to reports of the stresses on healthcare workers presented by the AIDS epidemic, and to calls in the burnout literature to examine coping responses in specific practice areas. Questionnaires were mailed to social workers in hospitals of over 350 beds in the ten states with the highest incidence of AIDS. The sample was comprised of 128 social workers who had provided services to 10 or more AIDS patients within the previous six months. The questionnaire measured background variables (demographic variables, work and practice characteristics), independent variables (stressors of practice with AIDS patients, potency and how difficult the social workers found their practice with AIDS patients) and dependent variables (burnout and physical symptoms). The research was guided by the theories of Lazarus, Maslach and Ben Sira. Univariate, bivariate and multivariate analyses were used to test hypothesized relationships between the dependent and independent variables. Background variables were used as controls. The analyses supported the hypotheses that stressors of practice with AIDS patients and difficulty in practice were correlated, and that potency interacts with stressors as they relate to difficulty. That is, in persons with high potency, the relationship between stressors and difficulty is lower than is the case in persons with low potency. The three measures of burnout were related to difficulty. Potency also had a strong direct effect on burnout and physical symptoms. The results suggest that potency is an important factor in burnout, and should be studied further. If substantiated in further research, the results imply that employers and educators need to develop strategies to increase the sense of mastery, self-confidence and faith in societal justness (potency) if they hope to decrease burnout in social workers who practice with AIDS patients.