OBJECTIVES: The coronavirus 2019 (COVID-19) pandemic has overwhelmed health care systems and disrupted routine care internationally. Health care workers face disruption to their work routines and professional development, as well as an elevated risk of infection and morbidity. We sought to establish the impact of the COVID-19 pandemic on the well-being, practice, and progression of all trainees in cardiothoracic surgery in the United Kingdom. METHODS: A 31-item questionnaire was designed, validated, and disseminated via e-mail and an instant-messaging platform. RESULTS: In total, 76 (of 118, 64%) cardiothoracic surgical trainees responded, representing all training grades and programs nationally; 48 (63%) and 24 (32%) were concerned about their physical and mental health, respectively, 25 (33%) had taken time off work due to COVID-19, 65 (86%) had treated patients with COVID-19, 36 of whom (55%) were wearing satisfactory personal protective equipment at the time, 41 (54%) remain concerned about personal protective equipment provision at their institution, 42 (55%) had been redeployed to cover other specialties, and 23 (30%) had encountered ethical dilemmas related to care of patients. There was a significant impact on time spent in outpatient clinics (44% reduction), multidisciplinary team meetings (79% reduction), and operating theaters (78% reduction). In total, 67 (88%) of respondents were concerned about the impact on their training, and 54 (71%) felt that the deviation may require an extension in their planned training time. CONCLUSIONS: The duration and impact of the current pandemic is, as yet, uncertain. Timely sharing of experiences, concerns, and expectations will inform health care and education policy and influence practice in the pandemic era and beyond.