<p><strong>OBJECTIVES: </strong>The COVID-19 pandemic has introduced strains in the diagnostic process through uncertainty in diagnosis, changes to usual clinical processes, and introduction of a unique social context of altered health care delivery and fear of the medical environment. These challenges created a context ripe for diagnostic error involving both systems and cognitive factors.</p>

<p><strong>CASE PRESENTATION: </strong>We present a series of three pediatric cases presenting to care during the early phases of the COVID-19 pandemic that highlight the heightened potential for diagnostic errors in the pandemic context with particular focus on the interplay of systems and cognitive factors leading to delayed and missed diagnoses. These cases illustrate the particular power of availability bias, diagnostic momentum, and premature closure in the diagnostic process.</p>

<p><strong>CONCLUSIONS: </strong>Through integrated commentary and a fishbone analysis of the cognitive and systems factors at play, these three cases emphasize the specific influence of the COVID-19 pandemic on pediatric patients.</p>