Aim This study investigated febrile children with petechial rashes who presented to European emergency departments (EDs) and investigated the role that mechanical causes played in diagnoses. Methods Consecutive patients with fever presenting to EDs in 11 European emergency departments in 2017–2018 were enrolled. The cause and focus of infection were identified and a detailed analysis was performed on children with petechial rashes. The results are presented as odds ratios (OR) with 95% confidence intervals (CI). Results We found that 453/34010 (1.3%) febrile children had petechial rashes. The focus of the infection included sepsis (10/453, 2.2%) and meningitis (14/453, 3.1%). Children with a petechial rash were more likely than other febrile children to have sepsis or meningitis (OR 8.5, 95% CI 5.3–13.1) and bacterial infections (OR 1.4, 95% CI 1.0–1.8) as well as need for immediate life‐saving interventions (OR 6.6, 95% CI 4.4–9.5) and intensive care unit admissions (OR 6.5, 95% CI 3.0–12.5). Conclusion The combination of fever and petechial rash is still an important warning sign for childhood sepsis and meningitis. Ruling out coughing and/or vomiting was insufficient to safely identify low‐risk patients.