ImportanceRacial implicit bias can contribute to health disparities through its negative influence on physician communication with Black patients. Interventions for physicians to address racial implicit bias in their clinical encounters are limited by a lack of high-fidelity (realistic) simulations to provide opportunities for skill development and practice.ObjectiveTo describe the development and initial evaluation of a high-fidelity simulation of conditions under which physicians might be influenced by implicit racial bias.Design, Setting, and ParticipantsThis cross-sectional study, performed on an online platform from March 1 to September 30, 2022, recruited a convenience sample of physician volunteers to pilot an educational simulation.ExposuresIn the simulation exercise, physicians saw a 52-year-old male standardized patient (SP) (presenting as Black or White) seeking urgent care for epigastric pain, nausea, and vomiting. The case included cognitive stressors common to clinical environments, including clinical ambiguity, stress, time constraints, and interruptions. Physicians explained their diagnosis and treatment plan to the SP, wrote an assessment and management plan, completed surveys, and took the Race Implicit Association Test (IAT) and Race Medical Cooperativeness IAT. The SPs, blinded to the purpose of the study, assessed each physician’s communication using skills checklists and global rating scales.Main Outcomes and MeasuresAssociation between physicians’ IAT scores and SP race with SP ratings of communication skills.ResultsIn 60 physicians (23 [38.3%] Asian, 4 [6.7%] Black, 23 [38.3%] White, and 10 [16.7%] other, including Latina/o/x, Middle Eastern, and multiracial; 31 [51.7%] female, 27 [45.0%] male, and 2 [3.3%] other), the interaction of physicians’ Race IAT score and SP race was significant for overall communication (mean [SD] β = −1.29 [0.41]), all subdomains of communication (mean [SD] β = −1.17 [0.52] to −1.43 [0.59]), and overall global ratings (mean [SD] β = −1.09 [0.39]). Black SPs rated physicians lower on communication skills for a given pro-White Race IAT score than White SPs; White SP ratings increased as physicians’ pro-White bias increased.Conclusions and RelevanceIn this cross-sectional study, a high-fidelity simulation calibrated with cognitive stressors common to clinical environments elicited the expected influence of racial implicit bias on physicians’ communication skills. The outlined process and preliminary results can inform the development and evaluation of interventions that seek to address racial implicit bias in clinical encounters and improve physician communication with Black patients.