Background: Graduate training is a high-risk period for worsening mental health. Previous research reported the effectiveness of a classroom-based self-care intervention for graduate students. Purpose: The study evaluated the effectiveness of an online self-care intervention for graduate-level students to prevent worsening mental health. Methods: Participants were 187 students in public health. The intervention consisted of behavior change assignments designed to increase health-promoting behaviors within four domains (nutrition, physical activity, mental health, social support). Students received bonus points for maintaining health behaviors for the duration of the 12-week semester. Outcomes included measures of nutrition, physical activity, depression, anxiety, and perceived stress. The study employed a control group of students not enrolled in the course (n = 29). Results: Health promotion behaviors increased over the course of the semester (ps<0.001), with the largest effect sizes for increases in fruit and vegetable intake and physical activity. Improvements in self-reported health were reported. Control students reported no improvements. Discussion: The study provides support for the utility of a brief self-care intervention for students in the health sciences. Translation to Health Education Practice: This disseminable intervention can support student well-being in a variety of academic programs. A AJHE Self-Study quiz is online for this article via the SHAPE America Online Institute (SAOI) http://portal.shapeamerica.org/trn-Webinars