AbstractBackgroundMany clinicians believe that a patient's body mass index (BMI) affects the likelihood of obtaining high quality ultrasound images.ObjectivesTo assess the hypothesis that increased BMI is associated with worsening focused assessment with sonography in trauma (FAST) image quality.MethodsWe conducted a retrospective single‐center study of FAST examinations performed in a large academic emergency department (ED) with fellowship‐trained emergency ultrasonography faculty performing quality assurance review.ResultsMean (SD) BMI was 28.0 (6.6) among the 302 included studies. The overall quality rating tended to decrease as BMI increased but did not achieve statistical significance in a univariable setting (P = .06) or after adjustment for age and sex (P = .06). Operators perception of image adequacy was largely unaffected by BMI, with the exception of the pericardial view.ConclusionThis study did not identify a statistically significant difference in FAST quality with increased BMI. This result may help assuage clinician concerns about ultrasonography for patients in the ED.