Forty medical residents from major teaching hospitals in Boston, Massachusetts, participated in small group teaching sessions about caregiver stress. A teaching tool was developed that included a teaching handout, interactive cases, standard instruments for assessing caregiver stress, peer-reviewed articles about caregiving, and a list of resources that would be useful to a caregiver. These materials and teaching format were evaluated using a pre- and posttest and a feedback form. Forty residents completed the pretest and posttest. They scored significantly higher on the posttest for questions that covered estimated cost of caregiving (p = 0.0073), physical stress from caregiving (p = 0.0196), and identifying elder abuse (p = 0.0006). Ninety percent of the residents completed the evaluation form and rated the intervention highly. Teaching medical residents about caregiver stress resulted in a significant increase in knowledge about this topic. This study makes the case for the integration of "Caregiver Stress" into the primary care residency curriculum. (Contains 1 table.)