Leadership behavior can affect employees’ ability to perform and thrive in organizational situations characterized by intense challenge or stress. We draw on the literatures on framing and on crisis to develop a leadership concept, optimistic realism, that describes a particular way of framing a situation. We define optimistic realism as the tendency to speak candidly about work challenges, while projecting a hopeful stance about the future. We hypothesize that leader behaviors that frame the situation with optimistic realism enable workers to learn, remain committed, and adapt. Leveraging survey data from clinicians in intensive care units across two time points during the early years of the COVID-19 pandemic (n=557 and n=153, respectively), we find that healthcare workers whose leaders convey both optimism and realism to a greater degree – comprising the optimistic realism construct – report more proactive learning, greater intent to stay with the organization, and less burnout, relative to those reporting low on both (all p-values <.01), and these relationships persist over time. Relative to workers whose leaders are low on both, workers with leaders who emphasize one dimension over the other report greater intent to stay but similar levels of proactive behavior, and different burnout effects. Our findings contribute to the crisis management and healthcare management literatures by identifying leader framing as a factor in mitigating adverse effects of crisis (e.g., less proactive learning), and by identifying optimistic realism as an effective frame for this goal. We discuss implications for healthcare leadership practice, where challenge is increasingly common.